Remove some null pointer checks. Null pointers in these areas indicate
programming errors, and I think it's better to oops immediately rather than
return an error that is easily ignored.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Adam Belay <ambx1@neo.rr.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
bitmap_active() no longer exists and BITMAP_ACTIVE is no longer used.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I_LOCK was used for several unrelated purposes, which caused deadlock
situations in certain filesystems as a side effect. One of the purposes
now uses the new I_SYNC bit.
Also document the various bits and change their order from historical to
logical.
[bunk@stusta.de: make fs/inode.c:wake_up_inode() static]
Signed-off-by: Joern Engel <joern@wohnheim.fh-wedel.de>
Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After making dirty a 100M file, the normal behavior is to start the writeback
for all data after 30s delays. But sometimes the following happens instead:
- after 30s: ~4M
- after 5s: ~4M
- after 5s: all remaining 92M
Some analyze shows that the internal io dispatch queues goes like this:
s_io s_more_io
-------------------------
1) 100M,1K 0
2) 1K 96M
3) 0 96M
1) initial state with a 100M file and a 1K file
2) 4M written, nr_to_write <= 0, so write more
3) 1K written, nr_to_write > 0, no more writes(BUG)
nr_to_write > 0 in (3) fools the upper layer to think that data have all been
written out. The big dirty file is actually still sitting in s_more_io. We
cannot simply splice s_more_io back to s_io as soon as s_io becomes empty, and
let the loop in generic_sync_sb_inodes() continue: this may starve newly
expired inodes in s_dirty. It is also not an option to draw inodes from both
s_more_io and s_dirty, an let the loop go on: this might lead to live locks,
and might also starve other superblocks in sync time(well kupdate may still
starve some superblocks, that's another bug).
We have to return when a full scan of s_io completes. So nr_to_write > 0 does
not necessarily mean that "all data are written". This patch introduces a
flag writeback_control.more_io to indicate this situation. With it the big
dirty file no longer has to wait for the next kupdate invocation 5s later.
Cc: David Chinner <dgc@sgi.com>
Cc: Ken Chen <kenchen@google.com>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NTFS's if-condition on dirty inodes is not complete. Fix it with
sb_has_dirty_inodes().
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Ken Chen <kenchen@google.com>
Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current -mm tree has bucketful of bug fixes in periodic writeback path.
However, we still hit a glitch where dirty pages on a given inode aren't
completely flushed to the disk, and system will accumulate large amount of
dirty pages beyond what dirty_expire_interval is designed for.
The problem is __sync_single_inode() will move an inode to sb->s_dirty list
even when there are more pending dirty pages on that inode. If there is
another inode with a small number of dirty pages, we hit a case where the loop
iteration in wb_kupdate() terminates prematurely because wbc.nr_to_write > 0.
Thus leaving the inode that has large amount of dirty pages behind and it has
to wait for another dirty_writeback_interval before we flush it again. We
effectively only write out MAX_WRITEBACK_PAGES every dirty_writeback_interval.
If the rate of dirtying is sufficiently high, the system will start
accumulate a large number of dirty pages.
So fix it by having another sb->s_more_io list on which to park the inode
while we iterate through sb->s_io and to allow each dirty inode which resides
on that sb to have an equal chance of flushing some amount of dirty pages.
Signed-off-by: Ken Chen <kenchen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
printk: add the KERN_CONT annotation (which is empty string but via
which checkpatch.pl can notice that the lacking KERN_ level is fine).
This useful for multiple calls of hand-crafted printk output done by
early debug code or similar.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One more small change to extend the availability of creation of file
descriptors with FD_CLOEXEC set. Adding a new command to fcntl() requires
no new system call and the overall impact on code size if minimal.
If this patch gets accepted we will also add this change to the next
revision of the POSIX spec.
To test the patch, use the following little program. Adjust the value of
F_DUPFD_CLOEXEC appropriately.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#ifndef F_DUPFD_CLOEXEC
# define F_DUPFD_CLOEXEC 12
#endif
int
main (int argc, char *argv[])
{
if (argc > 1)
{
if (fcntl (3, F_GETFD) == 0)
{
puts ("descriptor not closed");
exit (1);
}
if (errno != EBADF)
{
puts ("error not EBADF");
exit (1);
}
exit (0);
}
int fd = fcntl (STDOUT_FILENO, F_DUPFD_CLOEXEC, 0);
if (fd == -1 && errno == EINVAL)
{
puts ("F_DUPFD_CLOEXEC not supported");
return 0;
}
if (fd != 3)
{
puts ("program called with descriptors other than 0,1,2");
return 1;
}
execl ("/proc/self/exe", "/proc/self/exe", "1", NULL);
puts ("execl failed");
return 1;
}
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is nice 2 byte hole after struct task_struct::ioprio field
into which we can put two 1-byte fields: ->fpu_counter and ->oomkilladj.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For Michael Kerrisk request, the following patch renames signalfd_siginfo
fields in order to keep them consistent with the siginfo_t ones.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
CONFIG_EXT3_INDEX is not an exposed config option in the kernel, and it is
unconditionally defined in ext3_fs.h. tune2fs is already able to turn off
dir indexing, so at this point it's just cluttering up the code. Remove
it.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Only very little files use the deprecated SA_* IRQ flags in latest pull. This
patch series removes such macros from the tree and transfrom old code to the
new IRQF_* flags.
I've grepped the whole tree to make sure that no more files than the patched
ones use such deprecated macros. I hope this series won't introduce build
errors.
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Right now futexfs and inotifyfs have one magic 0xBAD1DEA, that looks a
little bit confusing. Use 0xBAD1DEA as magic for futexfs and 0x2BAD1DEA as
magic for inotifyfs.
Signed-off-by: Andrey Mirkin <major@openvz.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/asm-powerpc/elf.h has 6 entries in ARCH_DLINFO. fs/binfmt_elf.c
has 14 unconditional NEW_AUX_ENT entries and 2 conditional NEW_AUX_ENT
entries. So in the worst case, saved_auxv does not get an AT_NULL entry at
the end.
The saved_auxv array must be terminated with an AT_NULL entry. Make the
size of mm_struct->saved_auxv arch dependend, based on the number of
ARCH_DLINFO entries.
Signed-off-by: Olaf Hering <olh@suse.de>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The nslock spinlock is not used in the kernel at all. Remove it.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For those who deselect POSIX message queues.
Reduces SLAB size of user_struct from 64 to 32 bytes here, SLUB size -- from
40 bytes to 32 bytes.
[akpm@linux-foundation.org: fix build]
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds three new functions (or in one case to be more exact makes it
always available)
tty_termios_copy_hw
Copies all the hardware settings from one termios structure to the other.
This is intended for drivers that support little or no hardware setting
tty_termios_encode_baud_rate
Allows you to set the input and output baud rate in a termios structure. A
driver is supposed to set the resulting baud rate from a request so most
will want to use this function to set the resulting input and output rates
to match the hardware values. Internally it knows about keeping Bxxx
encoding when possible to maximise compatibility.
tty_encode_baud_rate
As above but for the tty's own current termios structure
I suspect this will initially need some tweaking as it gets enabled by
driver patches over the next few mm cycles so consider this lot -mm only
for the moment so it can stabilize and end up neat before it goes to base.
I've tried not to break any obscure architectures - if you get a speed you
can't represent the code will print warnings on non updated termios systems
but not break.
Once this is merged and seems sane I've got a growing pile of driver
updates to use it - notably for USB serial drivers.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add const modifiers to a few struct nls_table's member pointers in
include/linux/nls.h and adds a lot of const's in fs/nls/*.c files.
Resulting changes as visible by size:
text data bss dec hex filename
113612 481216 2368 597196 91ccc nls.org/built-in.o
593548 3296 288 597132 91c8c nls/built-in.o
Apparently compiler managed to optimize code a bit better
because of const-ness.
No other changes are made.
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes shrink_dcache_sb consistent with dentry pruning policy.
On the first pass we iterate over dentry unused list and prepare some
dentries for removal.
However, since the existing code moves evicted dentries to the beginning of
the LRU it can happen that fresh dentries from other superblocks will be
inserted *before* our dentries.
This can result in significant slowdown of shrink_dcache_sb(). Moreover,
for virtual filesystems like unionfs which can call dput() during dentries
kill existing code results in O(n^2) complexity.
We observed 2 minutes shrink_dcache_sb() with only 35000 dentries.
To avoid this effects we propose to isolate sb dentries at the end
of LRU list.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Kirill Korotaev <dev@openvz.org>
Signed-off-by: Andrey Mirkin <amirkin@openvz.org>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Other/Some pr_*() macros are already defined in kernel.h, but pr_err() was
defined multiple times in several other places
Signed-off-by: Emil Medve <Emilian.Medve@Freescale.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Tony Lindgren <tony@atomide.com>
Reviewed-by: Satyam Sharma <satyam@infradead.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make request_key() and co fundamentally asynchronous to make it easier for
NFS to make use of them. There are now accessor functions that do
asynchronous constructions, a wait function to wait for construction to
complete, and a completion function for the key type to indicate completion
of construction.
Note that the construction queue is now gone. Instead, keys under
construction are linked in to the appropriate keyring in advance, and that
anyone encountering one must wait for it to be complete before they can use
it. This is done automatically for userspace.
The following auxiliary changes are also made:
(1) Key type implementation stuff is split from linux/key.h into
linux/key-type.h.
(2) AF_RXRPC provides a way to allocate null rxrpc-type keys so that AFS does
not need to call key_instantiate_and_link() directly.
(3) Adjust the debugging macros so that they're -Wformat checked even if
they are disabled, and make it so they can be enabled simply by defining
__KDEBUG to be consistent with other code of mine.
(3) Documentation.
[alan@lxorguk.ukuu.org.uk: keys: missing word in documentation]
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As of now, the kernel defaults to non-unicode and XLATE for the keyboard.
We've been changing this in Fedora, but that requires patching the defaults
in the kernel.
The attached introduces CONFIG_VT_UNICODE, which sets the console in
unicode mode by default on boot, including both the virtual terminal and
the keyboard driver.
Signed-off-by: Bill Nottingham <notting@redhat.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
.. in an effort to make read-only whatever can be made, so that
CONFIG_DEBUG_RODATA can catch as many issues as possible.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__setup_str_* are referenced only during boot, hence there's no need to
waste image space for aligning these strings (with the aim of improving
performance).
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To go along with the existing "roundup_pow_of_two" routine, add one for
rounding down since that operation appears to crop up on a regular basis in
the source tree.
[m.kozlowski@tuxland.pl: fix unbalanced parentheses]
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement sending of quota messages via netlink interface. The advantage
is that in userspace we can better decide what to do with the message - for
example display a dialogue in your X session or just write the message to
the console. As a bonus, we can get rid of problems with console locking
deep inside filesystem code once we remove the old printing mechanism.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
{,un}register_timer_hook() is the API that should be used.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All asm/ipc.h files do only #include <asm-generic/ipc.h>.
This patch therefore removes all include/asm-*/ipc.h files and moves the
contents of include/asm-generic/ipc.h to include/linux/ipc.h.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm.h doesn't use directly anything from mutex.h and backing-dev.h, so
remove them and add them back to files which need them.
Cross-compile tested on many configs and archs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow NBD I/O to be cancelled when a network outage occurs. Previously, I/O
would just hang, and if enough I/O was hung in nbd, the system (at least
user-level) would completely hang until a TCP timeout (default, 15 minutes)
occurred.
The patch introduces a new ioctl NBD_SET_TIMEOUT that allows a transmit
timeout value (in seconds) to be specified. Any network send that exceeds the
timeout will be cancelled and the nbd connection will be shut down. I've
tested with various timeout values and 6 seconds seems to be a good choice for
the timeout. If the NBD_SET_TIMEOUT ioctl is not called, you get the old (I/O
hang) behavior.
Signed-off-by: Paul Clements <paul.clements@steeleye.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
No longer used. TTY_FLIPBUF_SIZE will also go soon but needs a couple of
other cleanups first
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
robust_list, compat_robust_list, pi_state_list, pi_state_cache are
really used if futexes are on.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a prefix "VMCOREINFO_" to the vmcoreinfo macros. Old vmcoreinfo macros
were defined as generic names SYMBOL/SIZE/OFFSET /LENGTH/CONFIG, and it is
impossible to grep for them. So these names should be changed. This
discussion is the following:
http://www.ussg.iu.edu/hypermail/linux/kernel/0709.1/0415.html
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[2/3] Add nodemask_t's size and NR_FREE_PAGES's value to vmcoreinfo_data.
The dump filetering command 'makedumpfile'(v1.1.6 or before) had assumed
the above values, and it was not good from the reliability viewpoint.
So makedumpfile v1.2.0 came to need these values and I created the patch
to let the kernel output them.
makedumpfile site:
https://sourceforge.net/projects/makedumpfile/
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[1/3] Cleanup the coding style according to Andrew's comments:
http://lists.infradead.org/pipermail/kexec/2007-August/000522.html
- vmcoreinfo_append_str() should have suitable __attribute__s so that
the compiler can check its use.
- vmcoreinfo_max_size should have size_t.
- Use get_seconds() instead of xtime.tv_sec.
- Use init_uts_ns.name.release instead of UTS_RELEASE.
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch set frees the restriction that makedumpfile users should install a
vmlinux file (including the debugging information) into each system.
makedumpfile command is the dump filtering feature for kdump. It creates a
small dumpfile by filtering unnecessary pages for the analysis. To
distinguish unnecessary pages, it needs a vmlinux file including the debugging
information. These days, the debugging package becomes a huge file, and it is
hard to install it into each system.
To solve the problem, kdump developers discussed it at lkml and kexec-ml. As
the result, we reached the conclusion that necessary information for dump
filtering (called "vmcoreinfo") should be embedded into the first kernel file
and it should be accessed through /proc/vmcore during the second kernel.
(http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.0/1806.html)
Dan Aloni created the patch set for the above implementation.
(http://www.uwsg.iu.edu/hypermail/linux/kernel/0707.1/1053.html)
And I updated it for multi architectures and memory models.
(http://lists.infradead.org/pipermail/kexec/2007-August/000479.html)
Signed-off-by: Dan Aloni <da-x@monatomic.org>
Signed-off-by: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix f_version type: should be u64 instead of long
There is a type inconsistency between struct inode i_version and struct file
f_version.
fs.h:
struct inode
u64 i_version;
and
struct file
unsigned long f_version;
Users do:
fs/ext3/dir.c:
if (filp->f_version != inode->i_version) {
So why isn't f_version a u64 ? It becomes a problem if versions gets
higher than 2^32 and we are on an architecture where longs are 32 bits.
This patch changes the f_version type to u64, and updates the users accordingly.
It applies to 2.6.23-rc2-mm2.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Martin Bligh <mbligh@google.com>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: <linux-ext4@vger.kernel.org>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
simple_commit_write() can now become static.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- remove the no longer required __attribute__((weak)) of xtime_lock
- remove the following no longer used EXPORT_SYMBOL's:
- xtime
- xtime_lock
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
oomkilladj is int, but values which can be assigned to it are -17, [-16,
15], thus fitting into s8.
While patch itself doesn't help in making task_struct smaller, because of
natural alignment of ->link_count, it will make picture clearer wrt futher
task_struct reduction patches. My plan is to move ->fpu_counter and
->oomkilladj after ->ioprio filling hole on i386 and x86_64. But that's
for later, because bloated distro configs need looking at as well.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The README file in the cramfs subdirectory says: "All data is currently in
host-endian format; neither mkcramfs nor the kernel ever do swabbing."
If somebody tries to mount a cramfs with the wrong endianess, cramfs only
complains about a wrong magic but doesn't inform the user that only the
endianess isn't right.
The following patch adds an error message to the cramfs sources. If a user
tries to mount a cramfs with the wrong endianess using the patched sources,
cramfs will display the message "cramfs: wrong endianess".
Signed-off-by: Andi Drebes <lists-receive@programmierforen.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/if_fddi.h is an exported header.
It uses __be16. Include linux/types.h to get this prototype.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove linux/consolemap.h from make headers_install
It contains no user interfaces.
The defines in this file are used only for kernel internal state.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There have been issues with non-latin1 diacritics and unicode.
http://bugzilla.kernel.org/show_bug.cgi?id=7746
Git 759448f459 `Kernel utf-8 handling'
partly resolved it by adding conversion between diacritics and
unicode. The patch below goes further by just turning diacritics into
unicode, hence providing better future support. The kbd support can be
fetched from
http://bugzilla.kernel.org/attachment.cgi?id=12313
This was tested in all of latin1, latin9, latin2 and unicode with french
and czech dead keys.
Turn the kernel accent_table into unicode, and extend ioctls KDGKBDIACR
and KDSKBDIACR into their equivalents KDGKBDIACRUC and KDSKBDIACR.
New function int conv_uni_to_8bit(u32 uni) for converting unicode into 8bit
_input_. No, we don't want to store the translation, as it is potentially
sparse and large.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Jan Engelhardt <jengelh@gmx.de>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds the MMF_DUMP_ELF_HEADERS option to /proc/pid/coredump_filter.
This dumps the first page (only) of a private file mapping if it appears to
be a mapping of an ELF file. Including these pages in the core dump may
give sufficient identifying information to associate the original DSO and
executable file images and their debugging information with a core file in
a generic way just from its contents (e.g. when those binaries were built
with ld --build-id). I expect this to become the default behavior
eventually. Existing versions of gdb can be confused by the core dumps it
creates, so it won't enabled by default for some time to come. Soon many
people will have systems with a gdb that handle these dumps, so they can
arrange to set the bit at boot and have it inherited system-wide.
This also cleans up the checking of the MMF_DUMP_* flag bits, which did not
need to be using atomic macros.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds the linux/elfcore-compat.h header file, which is the CONFIG_COMPAT
analog of the linux/elfcore.h header. Each arch that needs to fake out
fs/binfmt_elf.c for its compat code can use this header to replace the
hand-copied definitions of the compat variants of struct elf_prstatus et al.
Only the pr_reg field varies by arch, so asm/{compat,elf}.h must define
compat_elf_gregset_t before linux/elfcore-compat.h can be used.
It's a clean-up that every arch with compat core dumping code can benefit
from. I only touched the ones I have handy to test at home. Doing the same
for each other arch should be straightforward, and I'm happy to offer tips.
Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Andi Kleen <ak@suse.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move prototypes and in-core structures to fs/ufs/ similar to what most
other filesystems already do.
I made little modifications: move also ufs debug macros and
mount options constants into fs/ufs/ufs.h, this stuff
also private for ufs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add two new functions for reading the kernel log buffer. The intention is for
them to be used by recovery/dump/debug code so the kernel log can be easily
retrieved/parsed in a crash scenario, but they are generic enough for other
people to dream up other fun uses.
[akpm@linux-foundation.org: buncha fixes]
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Robin Getz <rgetz@blackfin.uclinux.org>
Cc: Greg Ungerer <gerg@snapgear.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds the /sys/module/<name>/notes/ magic directory, which has a
file for each allocated SHT_NOTE section that appears in <name>.ko. This
is the counterpart for each module of /sys/kernel/notes for vmlinux.
Reading this delivers the contents of the module's SHT_NOTE sections. This
lets userland easily glean any detailed information about that module's
build that was stored there at compile time (e.g. by ld --build-id).
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For some time /proc/sys/kernel/core_pattern has been able to set its output
destination as a pipe, allowing a user space helper to receive and
intellegently process a core. This infrastructure however has some
shortcommings which can be enhanced. Specifically:
1) The coredump code in the kernel should ignore RLIMIT_CORE limitation
when core_pattern is a pipe, since file system resources are not being
consumed in this case, unless the user application wishes to save the core,
at which point the app is restricted by usual file system limits and
restrictions.
2) The core_pattern code should be able to parse and pass options to the
user space helper as an argv array. The real core limit of the uid of the
crashing proces should also be passable to the user space helper (since it
is overridden to zero when called).
3) Some miscellaneous bugs need to be cleaned up (specifically the
recognition of a recursive core dump, should the user mode helper itself
crash. Also, the core dump code in the kernel should not wait for the user
mode helper to exit, since the same context is responsible for writing to
the pipe, and a read of the pipe by the user mode helper will result in a
deadlock.
This patch:
Remove the check of RLIMIT_CORE if core_pattern is a pipe. In the event that
core_pattern is a pipe, the entire core will be fed to the user mode helper.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Cc: <martin.pitt@ubuntu.com>
Cc: <wwoods@redhat.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add in support for SunOS 4.1.x flavor of BSD 4.2 UFS filing system Macros have
been put in to alow suport for the old static table Cylinder Groups but this
implementation does not use them yet.
This also fixes Solaris UFS filing system access by disabling fast symbolic
links as Sun's version of UFS does not support on-disk fast symbolic links.
Tested by:
Ppartitioning a new disk using SunOS 4.1.1, creating a UFS filing system on
one of the partitions and writing some files to the filing system.
Using Linux-2.6.22 (patched) to read the files and then write a shed load of
files to the UFS partition.
Using SunOS 4.1.1 to verify the filing system is OK and to check the files.
The test host is a sun4c SS1 Clone.
[akpm@linux-foundation.org: coding style fixes]
[adobriyan@gmail.com: fix oops]
Signed-off-by: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since the mempages parameter is actually not used, they should be removed.
Now there is only files_init use the mempages parameter,
files_init(mempages);
but I don't think the adaptation to mempages in files_init is really
useful; and if files_init also changed to the prototype void (*func)(void),
the wrapper vfs_caches_init would also not need the mempages parameter.
Signed-off-by: Denis Cheng <crquan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Adrian Bunk points out that "unsafe" was used to mark modules touched by
the deprecated MOD_INC_USE_COUNT interface, which has long gone. It's time
to remove the member from the module structure, as well.
If you want a module which can't unload, don't register an exit function.
(Vlad Yasevich says SCTP is now safe to unload, so just remove the
__unsafe there).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: Sridhar Samudrala <sri@us.ibm.com>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using mtab is problematic for various reasons, one of them is that
unprivileged mounts won't turn up in there. So we want to get rid of it, and
use /proc/mounts instead.
But most filesystems are lazy, and are not showing all mount options. Which
means, that without mtab, the user won't be able to see some or all of the
options.
It would be nice if the generic code could remember the mount options, and
show them without the need to add extra code to filesystems. But this is not
easy, because different filesystems handle mount options given options, and
not tough the rest. This is not taken into account by mount(8) either, so
/etc/mtab will be broken in this case.
This series fixes up ->show_options() in ext[234].
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rrrr, addition of sysctl.h to fs.h was't very smart, because simple
editing of the former will buy you big recompile, where it shouldn't
have to.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SHMLBA cant possible be used in userspace, see sparc versions of that header.
Do not export asm/shmparam.h during make headers_install_all
This removes another uservisible place of PAGE_SIZE
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The Synchronous Serial Controller (SSC) on Atmel microprocessors are
capable of tranceiving many frame based protocols, like I2S. Tested on the
AT32AP7000/ATSTK1000.
This driver is used in the ALSA sound driver for the AT73C213 external DAC
on the ATSTK1000 development board for AVR32. This sound driver will be
submitted soon.
Hardware documentation can be found in the AT32AP7000 data sheet, which can
be downloaded from
http://www.atmel.com/dyn/products/datasheets.asp?family_id=682
[akpm@linux-foundation.org: init spinlock at compile time]
Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Patrice Vilchez <patrice.vilchez@rfo.atmel.com>
Cc: Nicolas Ferre <nicolas.ferre@rfo.atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace worthless comments with actual preprocessor errors when including
the wrong versions of the compiler.h files.
[akpm@linux-foundation.org: make it work]
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Control the trigger limit for softlockup warnings. This is useful for
debugging softlockups, by lowering the softlockup_thresh to identify
possible softlockups earlier.
This patch:
1. Adds a sysctl softlockup_thresh with valid values of 1-60s
(Higher value to disable false positives)
2. Changes the softlockup printk to print the cpu softlockup time
[akpm@linux-foundation.org: Fix various warnings and add definition of "two"]
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Turns out that compiler writers are a bit more aggressive about optimizing
than one might expect. This patch prevents a number of such optimizations
from messing up rcu_deference(). This is not merely a theoretical problem, as
evidenced by the rmb() in mce_log().
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Josh Triplett <josh@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
list_del() hardly can fail, so checking for return value is pointless
(and current code always return 0).
Nobody really cared that return value anyway.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Switch single-linked binfmt formats list to usual list_head's. This leads
to one-liners in register_binfmt() and unregister_binfmt(). The downside
is one pointer more in struct linux_binfmt. This is not a problem, since
the set of registered binfmts on typical box is very small -- (ELF +
something distro enabled for you).
Test-booted, played with executable .txt files, modprobe/rmmod binfmt_misc.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- remove the following no longer used functions:
- bitmap.c: reiserfs_claim_blocks_to_be_allocated()
- bitmap.c: reiserfs_release_claimed_blocks()
- bitmap.c: reiserfs_can_fit_pages()
- make the following functions static:
- inode.c: restart_transaction()
- journal.c: reiserfs_async_progress_wait()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Vladimir V. Saveliev <vs@namesys.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduces new zone flag interface for testing and setting flags:
int zone_test_and_set_flag(struct zone *zone, zone_flags_t flag)
Instead of setting and clearing ZONE_RECLAIM_LOCKED each time shrink_zone() is
called, this flag is test and set before starting zone reclaim. Zone reclaim
starts in __alloc_pages() when a zone's watermark fails and the system is in
zone_reclaim_mode. If it's already in reclaim, there's no need to start again
so it is simply considered full for that allocation attempt.
There is a change of behavior with regard to concurrent zone shrinking. It is
now possible for try_to_free_pages() or kswapd to already be shrinking a
particular zone when __alloc_pages() starts zone reclaim. In this case, it is
possible for two concurrent threads to invoke shrink_zone() for a single zone.
This change forbids a zone to be in zone reclaim twice, which was always the
behavior, but allows for concurrent try_to_free_pages() or kswapd shrinking
when starting zone reclaim.
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Preprocess include/linux/oom.h before exporting it to userspace.
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's not necessary to include all of linux/sched.h in linux/oom.h. Instead,
simply include prototypes for the relevant structs and include linux/types.h
for gfp_t.
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Acked-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Instead of testing for overlap in the memory nodes of the the nearest
exclusive ancestor of both current and the candidate task, it is better to
simply test for intersection between the task's mems_allowed in their task
descriptors. This does not require taking callback_mutex since it is only
used as a hint in the badness scoring.
Tasks that do not have an intersection in their mems_allowed with the current
task are not explicitly restricted from being OOM killed because it is quite
possible that the candidate task has allocated memory there before and has
since changed its mems_allowed.
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
OOM killer synchronization should be done with zone granularity so that memory
policy and cpuset allocations may have their corresponding zones locked and
allow parallel kills for other OOM conditions that may exist elsewhere in the
system. DMA allocations can be targeted at the zone level, which would not be
possible if locking was done in nodes or globally.
Synchronization shall be done with a variation of "trylocks." The goal is to
put the current task to sleep and restart the failed allocation attempt later
if the trylock fails. Otherwise, the OOM killer is invoked.
Each zone in the zonelist that __alloc_pages() was called with is checked for
the newly-introduced ZONE_OOM_LOCKED flag. If any zone has this flag present,
the "trylock" to serialize the OOM killer fails and returns zero. Otherwise,
all the zones have ZONE_OOM_LOCKED set and the try_set_zone_oom() function
returns non-zero.
Cc: Andrea Arcangeli <andrea@suse.de>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Convert the int all_unreclaimable member of struct zone to unsigned long
flags. This can now be used to specify several different zone flags such as
all_unreclaimable and reclaim_in_progress, which can now be removed and
converted to a per-zone flag.
Flags are set and cleared as follows:
zone_set_flag(struct zone *zone, zone_flags_t flag)
zone_clear_flag(struct zone *zone, zone_flags_t flag)
Defines the first zone flags, ZONE_ALL_UNRECLAIMABLE and ZONE_RECLAIM_LOCKED,
which have the same semantics as the old zone->all_unreclaimable and
zone->reclaim_in_progress, respectively. Also converts all current users that
set or clear either flag to use the new interface.
Helper functions are defined to test the flags:
int zone_is_all_unreclaimable(const struct zone *zone)
int zone_is_reclaim_locked(const struct zone *zone)
All flag operators are of the atomic variety because there are currently
readers that are implemented that do not take zone->lock.
[akpm@linux-foundation.org: add needed include]
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The OOM killer's CONSTRAINT definitions are really more appropriate in an
enum, so define them in include/linux/oom.h.
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the OOM killer's extern function prototypes to include/linux/oom.h and
include it where necessary.
[clg@fr.ibm.com: build fix]
Cc: Andrea Arcangeli <andrea@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Slab constructors currently have a flags parameter that is never used. And
the order of the arguments is opposite to other slab functions. The object
pointer is placed before the kmem_cache pointer.
Convert
ctor(void *object, struct kmem_cache *s, unsigned long flags)
to
ctor(struct kmem_cache *s, void *object)
throughout the kernel
[akpm@linux-foundation.org: coupla fixes]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on ideas of Andrew:
http://marc.info/?l=linux-kernel&m=102912915020543&w=2
Scale the bdi dirty limit inversly with the tasks dirty rate.
This makes heavy writers have a lower dirty limit than the occasional writer.
Andrea proposed something similar:
http://lwn.net/Articles/152277/
The main disadvantage to his patch is that he uses an unrelated quantity to
measure time, which leaves him with a workload dependant tunable. Other than
that the two approaches appear quite similar.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Scale writeback cache per backing device, proportional to its writeout speed.
By decoupling the BDI dirty thresholds a number of problems we currently have
will go away, namely:
- mutual interference starvation (for any number of BDIs);
- deadlocks with stacked BDIs (loop, FUSE and local NFS mounts).
It might be that all dirty pages are for a single BDI while other BDIs are
idling. By giving each BDI a 'fair' share of the dirty limit, each one can have
dirty pages outstanding and make progress.
A global threshold also creates a deadlock for stacked BDIs; when A writes to
B, and A generates enough dirty pages to get throttled, B will never start
writeback until the dirty pages go away. Again, by giving each BDI its own
'independent' dirty limit, this problem is avoided.
So the problem is to determine how to distribute the total dirty limit across
the BDIs fairly and efficiently. A DBI that has a large dirty limit but does
not have any dirty pages outstanding is a waste.
What is done is to keep a floating proportion between the DBIs based on
writeback completions. This way faster/more active devices get a larger share
than slower/idle devices.
[akpm@linux-foundation.org: fix warnings]
[hugh@veritas.com: Fix occasional hang when a task couldn't get out of balance_dirty_pages]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Given a set of objects, floating proportions aims to efficiently give the
proportional 'activity' of a single item as compared to the whole set. Where
'activity' is a measure of a temporal property of the items.
It is efficient in that it need not inspect any other items of the set
in order to provide the answer. It is not even needed to know how many
other items there are.
It has one parameter, and that is the period of 'time' over which the
'activity' is measured.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide scalable per backing_dev_info statistics counters.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
provide a way to tell lockdep about percpu_counters that are supposed to be
used from irq safe contexts.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
alloc_percpu can fail, propagate that error.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide an accurate version of percpu_counter_read.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
s/percpu_counter_sum/&_positive/
Because its consitent with percpu_counter_read*
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Provide a method to set a percpu counter to a specified value.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
percpu_counter is a s64 counter, make _add consitent.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Because the current batch setup has an quadric error bound on the counter,
allow for an alternative setup.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hugh spotted that some code does:
percpu_counter_add(&counter, -unsignedlong)
which, when the amount argument is of type s32, sort-of works thanks to
two's-complement. However when we'd change the type to s64 this breaks on 32bit
machines, because the promotion rules zero extend the unsigned number.
Provide percpu_counter_sub() to hide the s64 cast. That is:
percpu_counter_sub(&counter, foo)
is equal to:
percpu_counter_add(&counter, -(s64)foo);
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
s/percpu_counter_mod/percpu_counter_add/
Because its a better name, _mod implies modulo.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These patches aim to improve balance_dirty_pages() and directly address three
issues:
1) inter device starvation
2) stacked device deadlocks
3) inter process starvation
1 and 2 are a direct result from removing the global dirty limit and using
per device dirty limits. By giving each device its own dirty limit is will
no longer starve another device, and the cyclic dependancy on the dirty limit
is broken.
In order to efficiently distribute the dirty limit across the independant
devices a floating proportion is used, this will allocate a share of the total
limit proportional to the device's recent activity.
3 is done by also scaling the dirty limit proportional to the current task's
recent dirty rate.
This patch:
nfs: remove congestion_end(). It's redundant, clear_bdi_congested() already
wakes the waiters.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update dump_task_altivec() (which has so far never been put to use) so that
it dumps the Altivec/VMX registers (VR[0] - VR[31], VSCR and VRSAVE) in the
same format as the ptrace get_vrregs(), and add the appropriate glue
typedef and #defines to make it work.
A new note type of NT_PPC_VMX was chosen to be 0x100 (arbitrarily) because
it allows the low range values to be used for more generic purposes and
0x100 seems an adequate starting point for PowerPC extensions.
Signed-off-by: Mark Nelson <markn@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Try to fix the mess created by sysfs braindamage.
- refactor code internal to fs/namei.c a little to avoid too much
duplication:
o __lookup_hash_kern is renamed back to __lookup_hash
o the old __lookup_hash goes away, permission checks moves to
the two callers
o useless inline qualifiers on above functions go away
- lookup_one_len_kern loses it's last argument and is renamed to
lookup_one_noperm to make it's useage a little more clear
- added kerneldoc comments to describe lookup_one_len aswell as
lookup_one_noperm and make it very clear that no one should use
the latter ever.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When CONFIG_SYSFS is not set, CONFIG_FAIR_USER_SCHED fails to build
with
kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1488): undefined reference to `kernel_subsys'
kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1490): undefined reference to `kernel_subsys'
kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1480): undefined reference to `kernel_subsys'
kernel/built-in.o: In function `uids_kobject_init':
(.init.text+0x1494): undefined reference to `kernel_subsys'
This patch fixes this build error.
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Extract generic of_device allocation code from of_platform_device_create()
and move it into of_device.[ch], called of_device_alloc(). Also, there's now
of_device_free() which puts the device node.
This way, bus drivers that build on of_platform (like ibmebus will) can
build upon this code instead of reinventing the wheel.
Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It reduces the selinux overhead on read/write by only revalidating
permissions in selinux_file_permission if the task or inode labels have
changed or the policy has changed since the open-time check. A new LSM
hook, security_dentry_open, is added to capture the necessary state at open
time to allow this optimization.
(see http://marc.info/?l=selinux&m=118972995207740&w=2)
Signed-off-by: Yuichi Nakamura<ynakam@hitachisoft.jp>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
This duplicates the read cycle timer feature of raw1394 (added in Linux
2.6.21) in firewire-core's userspace ABI. The argument to the ioctl is
reordered though to ensure 32/64 bit compatibility.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
* Add "hdx=nodma" option allowing user to disallow DMA for a given device.
* Obsolete "ide=nodma" option.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* hpt34x.c: disable DMA masks for HPT345
(hwif->autodma is zero so DMA won't be enabled anyway).
* trm290.c: disable IDE_HFLAG_TRUST_BIOS_FOR_DMA flag
(hwif->autodma is zero so DMA won't be enabled anyway).
* Check noautodma global variable instead of drive->autodma in ide_tune_dma().
This fixes handling of "ide=nodma" kernel parameter for icside, ide-cris,
au1xxx-ide, pmac, it821x, jmicron, sgiioc4 and siimage host drivers.
* Remove hwif->autodma (it was not checked by IDE core code anyway) and
drive->autodma (was set by all host drivers - except HPT345/TRM290 special
cases - unless "ide=nodma" was used).
While at it:
- remove needless printk() from icside.c
- remove stale FIXME/comment from ide-probe.c
- don't force DMA off if PCI bus-mastering had to be enabled in setup-pci.c
(this setting was always later over-ridden by host drivers anyway)
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Add IDE_HFLAG_TRUST_BIOS_FOR_DMA host flag for host drivers that depend
on BIOS for programming device/controller for DMA. Set it in cy82c693,
generic, ns87415, opti621 and trm290 host drivers.
* Add IDE_HFLAG_VDMA host flag for host drivers using VDMA. Set it in cs5520
host driver.
* Teach ide_tune_dma() about IDE_HFLAG_TRUST_BIOS_FOR_DMA flag.
* Add generic ide_dma_check() helper and remove all open coded ->ide_dma_check
implementations. Fix all places checking for presence of ->ide_dma_check
hook to check for ->ide_dma_on instead.
* Remove no longer needed code from config_drive_for_dma().
* Make ide_tune_dma() static.
v2:
* Fix config_drive_for_dma() return values.
* Fix ide-dma.c build for CONFIG_BLK_DEV_IDEDMA_PCI=n by adding
dummy config_drive_for_dma() inline.
* Fix IDE_HFLAG_TRUST_BIOS_FOR_DMA handling in ide_dma_check().
* Fix init_hwif_it8213() comment.
There should be no functionality changes caused by this patch.
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Remove ide_use_fast_pio() and just re-tune PIO unconditionally if DMA tuning
has failed in ->ide_dma_check. All host drivers using ide_use_fast_pio() set
drive->autotune so PIO is always tuned anyway and in some cases we _really_
need to re-tune PIO because PIO and DMA timings are shared.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (40 commits)
kbuild: introduce ccflags-y, asflags-y and ldflags-y
kbuild: enable 'make CPPFLAGS=...' to add additional options to CPP
kbuild: enable use of AFLAGS and CFLAGS on commandline
kbuild: enable 'make AFLAGS=...' to add additional options to AS
kbuild: fix AFLAGS use in h8300 and m68knommu
kbuild: check for wrong use of CFLAGS
kbuild: enable 'make CFLAGS=...' to add additional options to CC
kbuild: fix up CFLAGS usage
kbuild: make modpost detect unterminated device id lists
kbuild: call export_report from the Makefile
kbuild: move Kai Germaschewski to CREDITS
kconfig/menuconfig: distinguish between selected-by-another options and comments
kconfig: tristate choices with mixed tristate and boolean values
include/linux/Kbuild: remove duplicate entries
kbuild: kill backward compatibility checks
kbuild: kill EXTRA_ARFLAGS
kbuild: fix documentation in makefiles.txt
kbuild: call make once for all targets when O=.. is used
kbuild: pass -g to assembler under CONFIG_DEBUG_INFO
kbuild: update _shipped files for kconfig syntax cleanup
...
Fix up conflicts in arch/um/sys-{x86_64,i386}/Makefile manually.
* 'linus' of master.kernel.org:/pub/scm/linux/kernel/git/perex/alsa: (264 commits)
[ALSA] version 1.0.15
[ALSA] Fix thinko in cs4231 mce down check
[ALSA] sun-cs4231: improved waiting after MCE down
[ALSA] sun-cs4231: use cs4231-regs.h
[ALSA] This simplifies and fixes waiting loops of the mce_down()
[ALSA] This patch adds support for a wavetable chip on
[ALSA] This patch removes open_mutex from the ad1848-lib as
[ALSA] fix bootup crash in snd_gus_interrupt()
[ALSA] hda-codec - Fix SKU ID function for realtek codecs
[ALSA] Support ASUS P701 eeepc [0x1043 0x82a1] support
[ALSA] hda-codec - Add array terminator for dmic in STAC codec
[ALSA] hdsp - Fix zero division
[ALSA] usb-audio - Fix double comment
[ALSA] hda-codec - Fix STAC922x volume knob control
[ALSA] Changed Jaroslav Kysela's e-mail from perex@suse.cz to perex@perex.cz
[ALSA] hda-codec - Fix for Fujitsu Lifebook C1410
[ALSA] mpu-401: remove MPU401_INFO_UART_ONLY flag
[ALSA] mpu-401: do not require an ACK byte for the ENTER_UART command
[ALSA] via82xx - Add DXS quirk for Shuttle AK31v2
[ALSA] hda-codec - Fix input_mux numbers for vaio stac92xx
...
Move the extern declaration for global_mode_option to <linux/fb.h> and rename
the variable to fb_mode_option.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Various console drivers are able to resize the screen via the con_resize()
hook. This hook is also visible in userspace via the TIOCWINSZ, VT_RESIZE and
VT_RESIZEX ioctl's. One particular utility, SVGATextMode, expects that
con_resize() of the VGA console will always return success even if the
resulting screen is not compatible with the hardware. However, this
particular behavior of the VGA console, as reported in Kernel Bugzilla Bug
7513, can cause undefined behavior if the user starts with a console size
larger than 80x25.
To work around this problem, add an extra parameter to con_resize(). This
parameter is ignored by drivers except for vgacon. If this parameter is
non-zero, then the resize request came from a VT_RESIZE or VT_RESIZEX ioctl
and vgacon will always return success. If this parameter is zero, vgacon will
return -EINVAL if the requested size is not compatible with the hardware. The
latter is the more correct behavior.
With this change, SVGATextMode should still work correctly while in-kernel and
stty resize calls can expect correct behavior from vgacon.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Intel FB: allow odd- and even-field-first in interlaced modes, and
proper sync to vertical retrace
Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: <sylvain.meyer@worldonline.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow generic frame-buffer code to correctly write texts and blit images for
1, 2 and 4 bit per pixel frame-buffer organizations when pixels in bytes are
organized to in opposite order than bytes in long type.
Overhead should be reasonable. If option is not selected, than compiler
should eliminate completely all overhead.
The feature is disabled at compile time if CONFIG_FB_CFB_REV_PIXELS_IN_BYTE is
not set.
[adaplas]
Convert helper functions to macros if feature is not enabled.
Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
<linux/selection.h> assumes that struct tty_struct has previously been
included. If not, this pile of warnings will result:
CC [M] drivers/video/console/newport_con.o
In file included from drivers/video/console/newport_con.c:18:
include/linux/selection.h:16: warning: 'struct tty_struct' declared inside param
eter list
include/linux/selection.h:16: warning: its scope is only this definition or decl
aration, which is probably not what you want
include/linux/selection.h:17: warning: 'struct tty_struct' declared inside param
eter list
include/linux/selection.h:20: warning: 'struct tty_struct' declared inside param
eter list
Fixed by adding a forward declaration of struct tty_struct.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we setup the panel interface whilst configuring the
framebuffer, we should ensure the panel interface is not
in tristate, in case the bootloader or previous setup has
not enabled it.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add connector idx and val constants for v86d and uvesafb.
Signed-off-by: Michal Januszewski <spock@gentoo.org>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change the maximum message size to 16k to allow transfers of VBE
data blocks from userspace.
Signed-off-by: Michal Januszewski <spock@gentoo.org>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes the following needlessly global functions static:
- exp_get_by_name()
- exp_parent()
- exp_find()
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ISDN subsystem common functions use a semaphore as mutex. Use the
mutex API instead of the (binary) semaphore.
Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Acked-by: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce architecture dependent kretprobe blacklists to prohibit users
from inserting return probes on the function in which kprobes can be
inserted but kretprobes can not.
This patch also removes "__kprobes" mark from "__switch_to" on x86_64 and
registers "__switch_to" to the blacklist on x86-64, because that mark is to
prohibit user from inserting only kretprobe.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make the SPI framework and drivers stop using class_device. Update docs
accordingly ... highlighting just which sysfs paths should be
"safe"/stable.
Signed-off-by: Tony Jones <tonyj@suse.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the cpuset hooks that defined sched domains depending on the setting
of the 'cpu_exclusive' flag.
The cpu_exclusive flag can only be set on a child if it is set on the
parent.
This made that flag painfully unsuitable for use as a flag defining a
partitioning of a system.
It was entirely unobvious to a cpuset user what partitioning of sched
domains they would be causing when they set that one cpu_exclusive bit on
one cpuset, because it depended on what CPUs were in the remainder of that
cpusets siblings and child cpusets, after subtracting out other
cpu_exclusive cpusets.
Furthermore, there was no way on production systems to query the
result.
Using the cpu_exclusive flag for this was simply wrong from the get go.
Fortunately, it was sufficiently borked that so far as I know, almost no
successful use has been made of this. One real time group did use it to
affectively isolate CPUs from any load balancing efforts. They are willing
to adapt to alternative mechanisms for this, such as someway to manipulate
the list of isolated CPUs on a running system. They can do without this
present cpu_exclusive based mechanism while we develop an alternative.
There is a real risk, to the best of my understanding, of users
accidentally setting up a partitioned scheduler domains, inhibiting desired
load balancing across all their CPUs, due to the nonobvious (from the
cpuset perspective) side affects of the cpu_exclusive flag.
Furthermore, since there was no way on a running system to see what one was
doing with sched domains, this change will be invisible to any using code.
Unless they have real insight to the scheduler load balancing choices, they
will be unable to detect that this change has been made in the kernel's
behaviour.
Initial discussion on lkml of this patch has generated much comment. My
(probably controversial) take on that discussion is that it has reached a
rough concensus that the current cpuset cpu_exclusive mechanism for
defining sched domains is borked. There is no concensus on the
replacement. But since we can remove this mechanism, and since its
continued presence risks causing unwanted partitioning of the schedulers
load balancing, we should remove it while we can, as we proceed to work the
replacement scheduler domain mechanisms.
Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Cc: Dinakar Guniguntala <dino@in.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Direct Cache Access (DCA) is a method for warming the CPU cache before data
is used, with the intent of lessening the impact of cache misses. This
patch adds a manager and interface for matching up client requests for DCA
services with devices that offer DCA services.
In order to use DCA, a module must do bus writes with the appropriate tag
bits set to trigger a cache read for a specific CPU. However, different
CPUs and chipsets can require different sets of tag bits, and the methods
for determining the correct bits may be simple hardcoding or may be a
hardware specific magic incantation. This interface is a way for DCA
clients to find the correct tag bits for the targeted CPU without needing
to know the specifics.
[Dave Miller] use DEFINE_SPINLOCK()
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for MSI and MSI-X interrupt handling, including the ability
to choose the desired interrupt method.
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
[bunk@kernel.org: drivers/dma/ioat_dma.c: make 3 functions static]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add device ids for new revs of the Intel I/OAT DMA engine
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch contains the following cleanups:
- every file should include the headers containing the prototypes for
its global functions
- make the follosing needlessly global functions static:
- migrate_to_node()
- do_mbind()
- sp_alloc()
- mpol_rebind_policy()
[akpm@linux-foundation.org: fix uninitialised var warning]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes three needlessly global functions static.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The maximum size of the huge page pool can be controlled using the overall
size of the hugetlb filesystem (via its 'size' mount option). However in the
common case the this will not be set as the pool is traditionally fixed in
size at boot time. In order to maintain the expected semantics, we need to
prevent the pool expanding by default.
This patch introduces a new sysctl controlling dynamic pool resizing. When
this is enabled the pool will expand beyond its base size up to the size of
the hugetlb filesystem. It is disabled by default.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Dave McCracken <dave.mccracken@oracle.com>
Cc: William Irwin <bill.irwin@oracle.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Ken Chen <kenchen@google.com>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch is to avoid panic when memory hot-add is executed with
sparsemem-vmemmap. Current vmemmap-sparsemem code doesn't support memory
hot-add. Vmemmap must be populated when hot-add. This is for
2.6.23-rc2-mm2.
Todo: # Even if this patch is applied, the message "[xxxx-xxxx] potential
offnode page_structs" is displayed. To allocate memmap on its node,
memmap (and pgdat) must be initialized itself like chicken and
egg relationship.
# vmemmap_unpopulate will be necessary for followings.
- For cancel hot-add due to error.
- For unplug.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, arch dependent code around CONFIG_MEMORY_HOTREMOVE is a mess.
This patch cleans up them. This is against 2.6.23-rc6-mm1.
- fix compile failure on ia64/ CONFIG_MEMORY_HOTPLUG && !CONFIG_MEMORY_HOTREMOVE case.
- For !CONFIG_MEMORY_HOTREMOVE, add generic no-op remove_memory(),
which returns -EINVAL.
- removed remove_pages() only used in powerpc.
- removed no-op remove_memory() in i386, sh, sparc64, x86_64.
- only powerpc returns -ENOSYS at memory hot remove(no-op). changes it
to return -EINVAL.
Note:
Currently, only ia64 supports CONFIG_MEMORY_HOTREMOVE. I welcome other
archs if there are requirements and testers.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Logic.
- set all pages in [start,end) as isolated migration-type.
by this, all free pages in the range will be not-for-use.
- Migrate all LRU pages in the range.
- Test all pages in the range's refcnt is zero or not.
Todo:
- allocate migration destination page from better area.
- confirm page_count(page)== 0 && PageReserved(page) page is safe to be freed..
(I don't like this kind of page but..
- Find out pages which cannot be migrated.
- more running tests.
- Use reclaim for unplugging other memory type area.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement generic chunk-of-pages isolation method by using page grouping ops.
This patch add MIGRATE_ISOLATE to MIGRATE_TYPES. By this
- MIGRATE_TYPES increases.
- bitmap for migratetype is enlarged.
pages of MIGRATE_ISOLATE migratetype will not be allocated even if it is free.
By this, you can isolated *freed* pages from users. How-to-free pages is not
a purpose of this patch. You may use reclaim and migrate codes to free pages.
If start_isolate_page_range(start,end) is called,
- migratetype of the range turns to be MIGRATE_ISOLATE if
its type is MIGRATE_MOVABLE. (*) this check can be updated if other
memory reclaiming works make progress.
- MIGRATE_ISOLATE is not on migratetype fallback list.
- All free pages and will-be-freed pages are isolated.
To check all pages in the range are isolated or not, use test_pages_isolated(),
To cancel isolation, use undo_isolate_page_range().
Changes V6 -> V7
- removed unnecessary #ifdef
There are HOLES_IN_ZONE handling codes...I'm glad if we can remove them..
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A clean up patch for "scanning memory resource [start, end)" operation.
Now, find_next_system_ram() function is used in memory hotplug, but this
interface is not easy to use and codes are complicated.
This patch adds walk_memory_resouce(start,len,arg,func) function.
The function 'func' is called per valid memory resouce range in [start,pfn).
[pbadari@us.ibm.com: Error handling in walk_memory_resource()]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We touch a cacheline in the kmem_cache structure for zeroing to get the
size. However, the hot paths in slab_alloc and slab_free do not reference
any other fields in kmem_cache, so we may have to just bring in the
cacheline for this one access.
Add a new field to kmem_cache_cpu that contains the object size. That
cacheline must already be used in the hotpaths. So we save one cacheline
on every slab_alloc if we zero.
We need to update the kmem_cache_cpu object size if an aliasing operation
changes the objsize of an non debug slab.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kmem_cache_cpu structures introduced are currently an array placed in the
kmem_cache struct. Meaning the kmem_cache_cpu structures are overwhelmingly
on the wrong node for systems with a higher amount of nodes. These are
performance critical structures since the per node information has
to be touched for every alloc and free in a slab.
In order to place the kmem_cache_cpu structure optimally we put an array
of pointers to kmem_cache_cpu structs in kmem_cache (similar to SLAB).
However, the kmem_cache_cpu structures can now be allocated in a more
intelligent way.
We would like to put per cpu structures for the same cpu but different
slab caches in cachelines together to save space and decrease the cache
footprint. However, the slab allocators itself control only allocations
per node. We set up a simple per cpu array for every processor with
100 per cpu structures which is usually enough to get them all set up right.
If we run out then we fall back to kmalloc_node. This also solves the
bootstrap problem since we do not have to use slab allocator functions
early in boot to get memory for the small per cpu structures.
Pro:
- NUMA aware placement improves memory performance
- All global structures in struct kmem_cache become readonly
- Dense packing of per cpu structures reduces cacheline
footprint in SMP and NUMA.
- Potential avoidance of exclusive cacheline fetches
on the free and alloc hotpath since multiple kmem_cache_cpu
structures are in one cacheline. This is particularly important
for the kmalloc array.
Cons:
- Additional reference to one read only cacheline (per cpu
array of pointers to kmem_cache_cpu) in both slab_alloc()
and slab_free().
[akinobu.mita@gmail.com: fix cpu hotplug offline/online path]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: "Pekka Enberg" <penberg@cs.helsinki.fi>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We need the offset from the page struct during slab_alloc and slab_free. In
both cases we also reference the cacheline of the kmem_cache_cpu structure.
We can therefore move the offset field into the kmem_cache_cpu structure
freeing up 16 bits in the page struct.
Moving the offset allows an allocation from slab_alloc() without touching the
page struct in the hot path.
The only thing left in slab_free() that touches the page struct cacheline for
per cpu freeing is the checking of SlabDebug(page). The next patch deals with
that.
Use the available 16 bits to broaden page->inuse. More than 64k objects per
slab become possible and we can get rid of the checks for that limitation.
No need anymore to shrink the order of slabs if we boot with 2M sized slabs
(slub_min_order=9).
No need anymore to switch off the offset calculation for very large slabs
since the field in the kmem_cache_cpu structure is 32 bits and so the offset
field can now handle slab sizes of up to 8GB.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After moving the lockless_freelist to kmem_cache_cpu we no longer need
page->lockless_freelist. Restructure the use of the struct page fields in
such a way that we never touch the mapping field.
This is turn allows us to remove the special casing of SLUB when determining
the mapping of a page (needed for corner cases of virtual caches machines that
need to flush caches of processors mapping a page).
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A remote free may access the same page struct that also contains the lockless
freelist for the cpu slab. If objects have a short lifetime and are freed by
a different processor then remote frees back to the slab from which we are
currently allocating are frequent. The cacheline with the page struct needs
to be repeately acquired in exclusive mode by both the allocating thread and
the freeing thread. If this is frequent enough then performance will suffer
because of cacheline bouncing.
This patchset puts the lockless_freelist pointer in its own cacheline. In
order to make that happen we introduce a per cpu structure called
kmem_cache_cpu.
Instead of keeping an array of pointers to page structs we now keep an array
to a per cpu structure that--among other things--contains the pointer to the
lockless freelist. The freeing thread can then keep possession of exclusive
access to the page struct cacheline while the allocating thread keeps its
exclusive access to the cacheline containing the per cpu structure.
This works as long as the allocating cpu is able to service its request
from the lockless freelist. If the lockless freelist runs empty then the
allocating thread needs to acquire exclusive access to the cacheline with
the page struct lock the slab.
The allocating thread will then check if new objects were freed to the per
cpu slab. If so it will keep the slab as the cpu slab and continue with the
recently remote freed objects. So the allocating thread can take a series
of just freed remote pages and dish them out again. Ideally allocations
could be just recycling objects in the same slab this way which will lead
to an ideal allocation / remote free pattern.
The number of objects that can be handled in this way is limited by the
capacity of one slab. Increasing slab size via slub_min_objects/
slub_max_order may increase the number of objects and therefore performance.
If the allocating thread runs out of objects and finds that no objects were
put back by the remote processor then it will retrieve a new slab (from the
partial lists or from the page allocator) and start with a whole
new set of objects while the remote thread may still be freeing objects to
the old cpu slab. This may then repeat until the new slab is also exhausted.
If remote freeing has freed objects in the earlier slab then that earlier
slab will now be on the partial freelist and the allocating thread will
pick that slab next for allocation. So the loop is extended. However,
both threads need to take the list_lock to make the swizzling via
the partial list happen.
It is likely that this kind of scheme will keep the objects being passed
around to a small set that can be kept in the cpu caches leading to increased
performance.
More code cleanups become possible:
- Instead of passing a cpu we can now pass a kmem_cache_cpu structure around.
Allows reducing the number of parameters to various functions.
- Can define a new node_match() function for NUMA to encapsulate locality
checks.
Effect on allocations:
Cachelines touched before this patch:
Write: page cache struct and first cacheline of object
Cachelines touched after this patch:
Write: kmem_cache_cpu cacheline and first cacheline of object
Read: page cache struct (but see later patch that avoids touching
that cacheline)
The handling when the lockless alloc list runs empty gets to be a bit more
complicated since another cacheline has now to be written to. But that is
halfway out of the hot path.
Effect on freeing:
Cachelines touched before this patch:
Write: page_struct and first cacheline of object
Cachelines touched after this patch depending on how we free:
Write(to cpu_slab): kmem_cache_cpu struct and first cacheline of object
Write(to other): page struct and first cacheline of object
Read(to cpu_slab): page struct to id slab etc. (but see later patch that
avoids touching the page struct on free)
Read(to other): cpu local kmem_cache_cpu struct to verify its not
the cpu slab.
Summary:
Pro:
- Distinct cachelines so that concurrent remote frees and local
allocs on a cpuslab can occur without cacheline bouncing.
- Avoids potential bouncing cachelines because of neighboring
per cpu pointer updates in kmem_cache's cpu_slab structure since
it now grows to a cacheline (Therefore remove the comment
that talks about that concern).
Cons:
- Freeing objects now requires the reading of one additional
cacheline. That can be mitigated for some cases by the following
patches but its not possible to completely eliminate these
references.
- Memory usage grows slightly.
The size of each per cpu object is blown up from one word
(pointing to the page_struct) to one cacheline with various data.
So this is NR_CPUS*NR_SLABS*L1_BYTES more memory use. Lets say
NR_SLABS is 100 and a cache line size of 128 then we have just
increased SLAB metadata requirements by 12.8k per cpu.
(Another later patch reduces these requirements)
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch provides fragmentation avoidance statistics via /proc/pagetypeinfo.
The information is collected only on request so there is no runtime overhead.
The statistics are in three parts:
The first part prints information on the size of blocks that pages are
being grouped on and looks like
Page block order: 10
Pages per block: 1024
The second part is a more detailed version of /proc/buddyinfo and looks like
Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10
Node 0, zone DMA, type Unmovable 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Reclaimable 1 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Movable 0 0 0 0 0 0 0 0 0 0 0
Node 0, zone DMA, type Reserve 0 4 4 0 0 0 0 1 0 1 0
Node 0, zone Normal, type Unmovable 111 8 4 4 2 3 1 0 0 0 0
Node 0, zone Normal, type Reclaimable 293 89 8 0 0 0 0 0 0 0 0
Node 0, zone Normal, type Movable 1 6 13 9 7 6 3 0 0 0 0
Node 0, zone Normal, type Reserve 0 0 0 0 0 0 0 0 0 0 4
The third part looks like
Number of blocks type Unmovable Reclaimable Movable Reserve
Node 0, zone DMA 0 1 2 1
Node 0, zone Normal 3 17 94 4
To walk the zones within a node with interrupts disabled, walk_zones_in_node()
is introduced and shared between /proc/buddyinfo, /proc/zoneinfo and
/proc/pagetypeinfo to reduce code duplication. It seems specific to what
vmstat.c requires but could be broken out as a general utility function in
mmzone.c if there were other other potential users.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently mobility grouping works at the MAX_ORDER_NR_PAGES level. This makes
sense for the majority of users where this is also the huge page size.
However, on platforms like ia64 where the huge page size is runtime
configurable it is desirable to group at a lower order. On x86_64 and
occasionally on x86, the hugepage size may not always be MAX_ORDER_NR_PAGES.
This patch groups pages together based on the value of HUGETLB_PAGE_ORDER. It
uses a compile-time constant if possible and a variable where the huge page
size is runtime configurable.
It is assumed that grouping should be done at the lowest sensible order and
that the user would not want to override this. If this is not true,
page_block order could be forced to a variable initialised via a boot-time
kernel parameter.
One potential issue with this patch is that IA64 now parses hugepagesz with
early_param() instead of __setup(). __setup() is called after the memory
allocator has been initialised and the pageblock bitmaps already setup. In
tests on one IA64 there did not seem to be any problem with using
early_param() and in fact may be more correct as it guarantees the parameter
is handled before the parsing of hugepages=.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Grouping high-order atomic allocations together was intended to allow
bursty users of atomic allocations to work such as e1000 in situations
where their preallocated buffers were depleted. This did not work in at
least one case with a wireless network adapter needing order-1 allocations
frequently. To resolve that, the free pages used for min_free_kbytes were
moved to separate contiguous blocks with the patch
bias-the-location-of-pages-freed-for-min_free_kbytes-in-the-same-max_order_nr_pages-blocks.
It is felt that keeping the free pages in the same contiguous blocks should
be sufficient for bursty short-lived high-order atomic allocations to
succeed, maybe even with the e1000. Even if there is a failure, increasing
the value of min_free_kbytes will free pages as contiguous bloks in
contrast to the standard buddy allocator which makes no attempt to keep the
minimum number of free pages contiguous.
This patch backs out grouping high order atomic allocations together to
determine if it is really needed or not. If a new report comes in about
high-order atomic allocations failing, the feature can be reintroduced to
determine if it fixes the problem or not. As a side-effect, this patch
reduces by 1 the number of bits required to track the mobility type of
pages within a MAX_ORDER_NR_PAGES block.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Grouping pages by mobility can be disabled at compile-time. This was
considered undesirable by a number of people. However, in the current stack of
patches, it is not a simple case of just dropping the configurable patch as it
would cause merge conflicts. This patch backs out the configuration option.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The standard buddy allocator always favours the smallest block of pages.
The effect of this is that the pages free to satisfy min_free_kbytes tends
to be preserved since boot time at the same location of memory ffor a very
long time and as a contiguous block. When an administrator sets the
reserve at 16384 at boot time, it tends to be the same MAX_ORDER blocks
that remain free. This allows the occasional high atomic allocation to
succeed up until the point the blocks are split. In practice, it is
difficult to split these blocks but when they do split, the benefit of
having min_free_kbytes for contiguous blocks disappears. Additionally,
increasing min_free_kbytes once the system has been running for some time
has no guarantee of creating contiguous blocks.
On the other hand, CONFIG_PAGE_GROUP_BY_MOBILITY favours splitting large
blocks when there are no free pages of the appropriate type available. A
side-effect of this is that all blocks in memory tends to be used up and
the contiguous free blocks from boot time are not preserved like in the
vanilla allocator. This can cause a problem if a new caller is unwilling
to reclaim or does not reclaim for long enough.
A failure scenario was found for a wireless network device allocating
order-1 atomic allocations but the allocations were not intense or frequent
enough for a whole block of pages to be preserved for MIGRATE_HIGHALLOC.
This was reproduced on a desktop by booting with mem=256mb, forcing the
driver to allocate at order-1, running a bittorrent client (downloading a
debian ISO) and building a kernel with -j2.
This patch addresses the problem on the desktop machine booted with
mem=256mb. It works by setting aside a reserve of MAX_ORDER_NR_PAGES
blocks, the number of which depends on the value of min_free_kbytes. These
blocks are only fallen back to when there is no other free pages. Then the
smallest possible page is used just like the normal buddy allocator instead
of the largest possible page to preserve contiguous pages The pages in free
lists in the reserve blocks are never taken for another migrate type. The
results is that even if min_free_kbytes is set to a low value, contiguous
blocks will be preserved in the MIGRATE_RESERVE blocks.
This works better than the vanilla allocator because if min_free_kbytes is
increased, a new reserve block will be chosen based on the location of
reclaimable pages and the block will free up as contiguous pages. In the
vanilla allocator, no effort is made to target a block of pages to free as
contiguous pages and min_free_kbytes pages are scattered randomly.
This effect has been observed on the test machine. min_free_kbytes was set
initially low but it was kept as a contiguous free block within
MIGRATE_RESERVE. min_free_kbytes was then set to a higher value and over a
period of time, the free blocks were within the reserve and coalescing.
How long it takes to free up depends on how quickly LRU is rotating.
Amusingly, this means that more activity will free the blocks faster.
This mechanism potentially replaces MIGRATE_HIGHALLOC as it may be more
effective than grouping contiguous free pages together. It all depends on
whether the number of active atomic high allocations exceeds
min_free_kbytes or not. If the number of active allocations exceeds
min_free_kbytes, it's worth it but maybe in that situation, min_free_kbytes
should be set higher. Once there are no more reports of allocation
failures, a patch will be submitted that backs out MIGRATE_HIGHALLOC and
see if the reports stay missing.
Credit to Mariusz Kozlowski for discovering the problem, describing the
failure scenario and testing patches and scenarios.
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Acked-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are problems in the use of SPARSEMEM and pageblock flags that causes
problems on ia64.
The first part of the problem is that units are incorrect in
SECTION_BLOCKFLAGS_BITS computation. This results in a map_section's
section_mem_map being treated as part of a bitmap which isn't good. This
was evident with an invalid virtual address when mem_init attempted to free
bootmem pages while relinquishing control from the bootmem allocator.
The second part of the problem occurs because the pageblock flags bitmap is
be located with the mem_section. The SECTIONS_PER_ROOT computation using
sizeof (mem_section) may not be a power of 2 depending on the size of the
bitmap. This renders masks and other such things not power of 2 base.
This issue was seen with SPARSEMEM_EXTREME on ia64. This patch moves the
bitmap outside of mem_section and uses a pointer instead in the
mem_section. The bitmaps are allocated when the section is being
initialised.
Note that sparse_early_usemap_alloc() does not use alloc_remap() like
sparse_early_mem_map_alloc(). The allocation required for the bitmap on
x86, the only architecture that uses alloc_remap is typically smaller than
a cache line. alloc_remap() pads out allocations to the cache size which
would be a needless waste.
Credit to Bob Picco for identifying the original problem and effecting a
fix for the SECTION_BLOCKFLAGS_BITS calculation. Credit to Andy Whitcroft
for devising the best way of allocating the bitmaps only when required for
the section.
[wli@holomorphy.com: warning fix]
Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: William Irwin <bill.irwin@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In rare cases, the kernel needs to allocate a high-order block of pages
without sleeping. For example, this is the case with e1000 cards configured
to use jumbo frames. Migrating or reclaiming pages in this situation is not
an option.
This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE. The MIGRATE_HIGHATOMIC type are exactly what they sound
like. Care is taken that pages of other migrate types do not use the same
blocks as high-order atomic allocations.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations. When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.
This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE. The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved. i.e. they can be migrated by deleting
them and re-reading the information from elsewhere.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The grouping mechanism has some memory overhead and a more complex allocation
path. This patch allows the strategy to be disabled for small memory systems
or if it is known the workload is suffering because of the strategy. It also
acts to show where the page groupings strategy interacts with the standard
buddy allocator.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Joel Schopp <jschopp@austin.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds the core of the fragmentation reduction strategy. It works by
grouping pages together based on their ability to migrate or be reclaimed.
Basically, it works by breaking the list in zone->free_area list into
MIGRATE_TYPES number of lists.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Here is the latest revision of the anti-fragmentation patches. Of particular
note in this version is special treatment of high-order atomic allocations.
Care is taken to group them together and avoid grouping pages of other types
near them. Artifical tests imply that it works. I'm trying to get the
hardware together that would allow setting up of a "real" test. If anyone
already has a setup and test that can trigger the atomic-allocation problem,
I'd appreciate a test of these patches and a report. The second major change
is that these patches will apply cleanly with patches that implement
anti-fragmentation through zones.
kernbench shows effectively no performance difference varying between -0.2%
and +2% on a variety of test machines. Success rates for huge page allocation
are dramatically increased. For example, on a ppc64 machine, the vanilla
kernel was only able to allocate 1% of memory as a hugepage and this was due
to a single hugepage reserved as min_free_kbytes. With these patches applied,
17% was allocatable as superpages. With reclaim-related fixes from Andy
Whitcroft, it was 40% and further reclaim-related improvements should increase
this further.
Changelog Since V28
o Group high-order atomic allocations together
o It is no longer required to set min_free_kbytes to 10% of memory. A value
of 16384 in most cases will be sufficient
o Now applied with zone-based anti-fragmentation
o Fix incorrect VM_BUG_ON within buffered_rmqueue()
o Reorder the stack so later patches do not back out work from earlier patches
o Fix bug were journal pages were being treated as movable
o Bias placement of non-movable pages to lower PFNs
o More agressive clustering of reclaimable pages in reactions to workloads
like updatedb that flood the size of inode caches
Changelog Since V27
o Renamed anti-fragmentation to Page Clustering. Anti-fragmentation was giving
the mistaken impression that it was the 100% solution for high order
allocations. Instead, it greatly increases the chances high-order
allocations will succeed and lays the foundation for defragmentation and
memory hot-remove to work properly
o Redefine page groupings based on ability to migrate or reclaim instead of
basing on reclaimability alone
o Get rid of spurious inits
o Per-cpu lists are no longer split up per-type. Instead the per-cpu list is
searched for a page of the appropriate type
o Added more explanation commentary
o Fix up bug in pageblock code where bitmap was used before being initalised
Changelog Since V26
o Fix double init of lists in setup_pageset
Changelog Since V25
o Fix loop order of for_each_rclmtype_order so that order of loop matches args
o gfpflags_to_rclmtype uses gfp_t instead of unsigned long
o Rename get_pageblock_type() to get_page_rclmtype()
o Fix alignment problem in move_freepages()
o Add mechanism for assigning flags to blocks of pages instead of page->flags
o On fallback, do not examine the preferred list of free pages a second time
The purpose of these patches is to reduce external fragmentation by grouping
pages of related types together. When pages are migrated (or reclaimed under
memory pressure), large contiguous pages will be freed.
This patch works by categorising allocations by their ability to migrate;
Movable - The pages may be moved with the page migration mechanism. These are
generally userspace pages.
Reclaimable - These are allocations for some kernel caches that are
reclaimable or allocations that are known to be very short-lived.
Unmovable - These are pages that are allocated by the kernel that
are not trivially reclaimed. For example, the memory allocated for a
loaded module would be in this category. By default, allocations are
considered to be of this type
HighAtomic - These are high-order allocations belonging to callers that
cannot sleep or perform any IO. In practice, this is restricted to
jumbo frame allocation for network receive. It is assumed that the
allocations are short-lived
Instead of having one MAX_ORDER-sized array of free lists in struct free_area,
there is one for each type of reclaimability. Once a 2^MAX_ORDER block of
pages is split for a type of allocation, it is added to the free-lists for
that type, in effect reserving it. Hence, over time, pages of the different
types can be clustered together.
When the preferred freelists are expired, the largest possible block is taken
from an alternative list. Buddies that are split from that large block are
placed on the preferred allocation-type freelists to mitigate fragmentation.
This implementation gives best-effort for low fragmentation in all zones.
Ideally, min_free_kbytes needs to be set to a value equal to 4 * (1 <<
(MAX_ORDER-1)) pages in most cases. This would be 16384 on x86 and x86_64 for
example.
Our tests show that about 60-70% of physical memory can be allocated on a
desktop after a few days uptime. In benchmarks and stress tests, we are
finding that 80% of memory is available as contiguous blocks at the end of the
test. To compare, a standard kernel was getting < 1% of memory as large pages
on a desktop and about 8-12% of memory as large pages at the end of stress
tests.
Following this email are 12 patches that implement thie page grouping feature.
The first patch introduces a mechanism for storing flags related to a whole
block of pages. Then allocations are split between movable and all other
allocations. Following that are patches to deal with per-cpu pages and make
the mechanism configurable. The next patch moves free pages between lists
when partially allocated blocks are used for pages of another migrate type.
The second last patch groups reclaimable kernel allocations such as inode
caches together. The final patch related to groupings keeps high-order atomic
allocations.
The last two patches are more concerned with control of fragmentation. The
second last patch biases placement of non-movable allocations towards the
start of memory. This is with a view of supporting memory hot-remove of DIMMs
with higher PFNs in the future. The biasing could be enforced a lot heavier
but it would cost. The last patch agressively clusters reclaimable pages like
inode caches together.
The fragmentation reduction strategy needs to track if pages within a block
can be moved or reclaimed so that pages are freed to the appropriate list.
This patch adds a bitmap for flags affecting a whole a MAX_ORDER block of
pages.
In non-SPARSEMEM configurations, the bitmap is stored in the struct zone and
allocated during initialisation. SPARSEMEM statically allocates the bitmap in
a struct mem_section so that bitmaps do not have to be resized during memory
hotadd. This wastes a small amount of memory per unused section (usually
sizeof(unsigned long)) but the complexity of dynamically allocating the memory
is quite high.
Additional credit to Andy Whitcroft who reviewed up an earlier implementation
of the mechanism an suggested how to make it a *lot* cleaner.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The function of GFP_LEVEL_MASK seems to be unclear. In order to clear up
the mystery we get rid of it and replace GFP_LEVEL_MASK with 3 sets of GFP
flags:
GFP_RECLAIM_MASK Flags used to control page allocator reclaim behavior.
GFP_CONSTRAINT_MASK Flags used to limit where allocations can occur.
GFP_SLAB_BUG_MASK Flags that the slab allocator BUG()s on.
These replace the uses of GFP_LEVEL mask in the slab allocators and in
vmalloc.c.
The use of the flags not included in these sets may occur as a result of a
slab allocation standing in for a page allocation when constructing scatter
gather lists. Extraneous flags are cleared and not passed through to the
page allocator. __GFP_MOVABLE/RECLAIMABLE, __GFP_COLD and __GFP_COMP will
now be ignored if passed to a slab allocator.
Change the allocation of allocator meta data in SLAB and vmalloc to not
pass through flags listed in GFP_CONSTRAINT_MASK. SLAB already removes the
__GFP_THISNODE flag for such allocations. Generalize that to also cover
vmalloc. The use of GFP_CONSTRAINT_MASK also includes __GFP_HARDWALL.
The impact of allocator metadata placement on access latency to the
cachelines of the object itself is minimal since metadata is only
referenced on alloc and free. The attempt is still made to place the meta
data optimally but we consistently allow fallback both in SLAB and vmalloc
(SLUB does not need to allocate metadata like that).
Allocator metadata may serve multiple in kernel users and thus should not
be subject to the limitations arising from a single allocation context.
[akpm@linux-foundation.org: fix fallback_alloc()]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
