Commit Graph

504 Commits

Author SHA1 Message Date
Michael S. Tsirkin
f822566165 [PATCH] madvise MADV_DONTFORK/MADV_DOFORK
Currently, copy-on-write may change the physical address of a page even if the
user requested that the page is pinned in memory (either by mlock or by
get_user_pages).  This happens if the process forks meanwhile, and the parent
writes to that page.  As a result, the page is orphaned: in case of
get_user_pages, the application will never see any data hardware DMA's into
this page after the COW.  In case of mlock'd memory, the parent is not getting
the realtime/security benefits of mlock.

In particular, this affects the Infiniband modules which do DMA from and into
user pages all the time.

This patch adds madvise options to control whether memory range is inherited
across fork.  Useful e.g.  for when hardware is doing DMA from/into these
pages.  Could also be useful to an application wanting to speed up its forks
by cutting large areas out of consideration.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Acked-by: Hugh Dickins <hugh@veritas.com>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14 16:09:34 -08:00
Hugh Dickins
d98c7a0984 [PATCH] compound page: default destructor
Somehow I imagined that calling a NULL destructor would free a compound page
rather than oopsing.  No, we must supply a default destructor, __free_pages_ok
using the order noted by prep_compound_page.  hugetlb can still replace this
as before with its own free_huge_page pointer.

The case that needs this is not common: rarely does put_compound_page's
put_page_testzero bring the count down to 0.  But if get_user_pages is applied
to some part of a compound page, without immediate release (e.g.  AIO or
Infiniband), then it's possible for its put_page to come after the containing
vma has been unmapped and the driver done its free_pages.

That's just the kind of case compound pages are supposed to be guarding
against (but Nick points out, nor did PageReserved handle this right).

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14 16:09:33 -08:00
Hugh Dickins
41d78ba550 [PATCH] compound page: use page[1].lru
If a compound page has its own put_page_testzero destructor (the only current
example is free_huge_page), that is noted in page[1].mapping of the compound
page.  But that's rather a poor place to keep it: functions which call
set_page_dirty_lock after get_user_pages (e.g.  Infiniband's
__ib_umem_release) ought to be checking first, otherwise set_page_dirty is
liable to crash on what's not the address of a struct address_space.

And now I'm about to make that worse: it turns out that every compound page
needs a destructor, so we can no longer rely on hugetlb pages going their own
special way, to avoid further problems of page->mapping reuse.  For example,
not many people know that: on 50% of i386 -Os builds, the first tail page of a
compound page purports to be PageAnon (when its destructor has an odd
address), which surprises page_add_file_rmap.

Keep the compound page destructor in page[1].lru.next instead.  And to free up
the common pairing of mapping and index, also move compound page order from
index to lru.prev.  Slab reuses page->lru too: but if we ever need slab to use
compound pages, it can easily stack its use above this.

(akpm: decoded version of the above: the tail pages of a compound page now
have ->mapping==NULL, so there's no need for the set_page_dirty[_lock]()
caller to check that they're not compund pages before doing the dirty).

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-14 16:09:33 -08:00
Christoph Lameter
2903fb1694 [PATCH] vmscan: skip reclaim_mapped determination if we do not swap
This puts the variables and the way to get to reclaim_mapped in one block.
And allows zone_reclaim or other things to skip the determination (maybe
this whole block of code does not belong into refill_inactive_zone()?)

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-11 21:41:11 -08:00
Christoph Lameter
072eaa5d9c [PATCH] vmscan: remove duplicate increment of reclaim_in_progress
shrink_zone() already increments reclaim_in_progress.  No need to do it in
balance_pgdat.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-11 21:41:11 -08:00
Christoph Lameter
80e4342601 [PATCH] zone reclaim: do not check references to a page during zone reclaim
shrink_list() and refill_inactive() check all ptes pointing to a page for
reference bits in order to decide if the page should be put on the active
list.  This is not necessary for zone_reclaim since we are only interested
in removing unmapped pages.  Skip the checks in both functions.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-11 21:41:11 -08:00
Christoph Lameter
418aade459 [PATCH] Updates for page migration
This adds some additional comments in order to help others figure out how
exactly the code works.  And fix a variable name.

Also swap_page does need to ignore all reference bits when unmapping a
page.  Otherwise we may have to repeatedly unmap a frequently touched page.
So change the try_to_unmap parameter to 1.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-10 08:13:13 -08:00
Ravikiran G Thirumalai
f0188f4748 [PATCH] slab: Avoid deadlock at kmem_cache_create/kmem_cache_destroy
Prevents deadlock situation between
kmem_cache_create()/kmem_cache_destory(), and kmem_cache_create() /cpu
hotplug.  The locking order probably got moved over time.

Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-10 08:13:12 -08:00
Ingo Molnar
9934a7939e [PATCH] SLOB=y && SMP=y fix
fix CONFIG_SLOB=y (when CONFIG_SMP=y): get rid of the 'align' parameter
from its __alloc_percpu() implementation. Boot-tested on x86.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-08 07:52:58 -08:00
Nick Piggin
8519fb30e4 [PATCH] mm: compound release fix
Compound pages on SMP systems can now often be freed from pagetables via
the release_pages path.  This uses put_page_testzero which does not handle
compound pages at all.  Releasing constituent pages from process mappings
decrements their count to a large negative number and leaks the reference
at the head page - net result is a memory leak.

The problem was hidden because the debug check in put_page_testzero itself
actually did take compound pages into consideration.

Fix the bug and the debug check.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-07 16:12:33 -08:00
Christoph Lameter
0df420d8b6 [PATCH] hugetlbpage: return VM_FAULT_OOM on oom
Remove wrong and misleading comments.

Return VM_FAULT_OOM if the hugetlbpage fault handler cannot allocate a
page.  do_no_page will end up doing do_exit(SIGKILL).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-07 16:12:31 -08:00
David Gibson
a2dfef6947 [PATCH] Hugepages need clear_user_highpage() not clear_highpage()
When hugepages are newly allocated to a file in mm/hugetlb.c, we clear them
with a call to clear_highpage() on each of the subpages.  We should be
using clear_user_highpage(): on powerpc, at least, clear_highpage() doesn't
correctly mark the page as icache dirty so if the page is executed shortly
after it's possible to get strange results.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-07 16:12:31 -08:00
Linus Torvalds
7a21ef6fe9 mm/slab.c (non-NUMA): Fix compile warning and clean up code
The non-NUMA case would do an unmatched "free_alien_cache()" on an alien
pointer that had never been allocated.

It might not matter from a code generation standpoint (since in the
non-NUMA case, the code doesn't actually _do_ anything), but it not only
results in a compiler warning, it's really really ugly too.

Fix the compiler warning by just having a matching dummy allocation.
That also avoids an unnecessary #ifdef in the code.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-05 11:26:38 -08:00
Ravikiran G Thirumalai
4484ebf12b [PATCH] NUMA slab locking fixes: fix cpu down and up locking
This fixes locking and bugs in cpu_down and cpu_up paths of the NUMA slab
allocator.  Sonny Rao <sonny@burdell.org> reported problems sometime back on
POWER5 boxes, when the last cpu on the nodes were being offlined.  We could
not reproduce the same on x86_64 because the cpumask (node_to_cpumask) was not
being updated on cpu down.  Since that issue is now fixed, we can reproduce
Sonny's problems on x86_64 NUMA, and here is the fix.

The problem earlier was on CPU_DOWN, if it was the last cpu on the node to go
down, the array_caches (shared, alien) and the kmem_list3 of the node were
being freed (kfree) with the kmem_list3 lock held.  If the l3 or the
array_caches were to come from the same cache being cleared, we hit on
badness.

This patch cleans up the locking in cpu_up and cpu_down path.  We cannot
really free l3 on cpu down because, there is no node offlining yet and even
though a cpu is not yet up, node local memory can be allocated for it.  So l3s
are usually allocated at keme_cache_create and destroyed at
kmem_cache_destroy.  Hence, we don't need cachep->spinlock protection to get
to the cachep->nodelist[nodeid] either.

Patch survived onlining and offlining on a 4 core 2 node Tyan box with a 4
dbench process running all the time.

Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Cc: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-05 11:06:53 -08:00
Ravikiran G Thirumalai
ca3b9b9173 [PATCH] NUMA slab locking fixes: irq disabling from cahep->spinlock to l3 lock
Earlier, we had to disable on chip interrupts while taking the
cachep->spinlock because, at cache_grow, on every addition of a slab to a slab
cache, we incremented colour_next which was protected by the cachep->spinlock,
and cache_grow could occur at interrupt context.  Since, now we protect the
per-node colour_next with the node's list_lock, we do not need to disable on
chip interrupts while taking the per-cache spinlock, but we just need to
disable interrupts when taking the per-node kmem_list3 list_lock.

Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Cc: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-05 11:06:53 -08:00
Ravikiran G Thirumalai
2e1217cf96 [PATCH] NUMA slab locking fixes: move color_next to l3
colour_next is used as an index to add a colouring offset to a new slab in the
cache (colour_off * colour_next).  Now with the NUMA aware slab allocator, it
makes sense to colour slabs added on the same node sequentially with
colour_next.

This patch moves the colouring index "colour_next" per-node by placing it on
kmem_list3 rather than kmem_cache.

This also helps simplify locking for CPU up and down paths.

Signed-off-by: Alok N Kataria <alokk@calsoftinc.com>
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Shai Fultheim <shai@scalex86.org>
Cc: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-05 11:06:53 -08:00
Christoph Lameter
64b4a954b0 [PATCH] hugetlb: add comment explaining reasons for Bus Errors
I just spent some time researching a Bus Error.  Turns out that the huge
page fault handler can return VM_FAULT_SIGBUS for various conditions where
no huge page is available.

Add a note explaining the reasoning in the source.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-05 11:06:53 -08:00
Eric Dumazet
88a2a4ac6b [PATCH] percpu data: only iterate over possible CPUs
percpu_data blindly allocates bootmem memory to store NR_CPUS instances of
cpudata, instead of allocating memory only for possible cpus.

As a preparation for changing that, we need to convert various 0 -> NR_CPUS
loops to use for_each_cpu().

(The above only applies to users of asm-generic/percpu.h.  powerpc has gone it
alone and is presently only allocating memory for present CPUs, so it's
currently corrupting memory).

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <axboe@suse.de>
Cc: Anton Blanchard <anton@samba.org>
Acked-by: William Irwin <wli@holomorphy.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-05 11:06:51 -08:00
Chen, Kenneth W
00ac59adfc [PATCH] x86_64: Fix memory policy build without CONFIG_HUGETLBFS
> mm/mempolicy.c: In function `huge_zonelist':
> mm/mempolicy.c:1045: error: `HPAGE_SHIFT' undeclared (first use in this function)
> mm/mempolicy.c:1045: error: (Each undeclared identifier is reported only once
> mm/mempolicy.c:1045: error: for each function it appears in.)
> make[1]: *** [mm/mempolicy.o] Error 1

Need to wrap huge_zonelist function with CONFIG_HUGETLBFS.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-04 16:43:14 -08:00
Randy Dunlap
ee13d785ea [PATCH] slab: fix sparse warning
mm/slab.c:1522:13: error: incompatible types for operation (&)

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:18 -08:00
Randy.Dunlap
a70773ddb9 [PATCH] mm/slab: add kernel-doc for one function
Fix kernel-doc for calculate_slab_order().

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:18 -08:00
Pekka Enberg
7fd6b14130 [PATCH] slab: fix kzalloc and kstrdup caller report for CONFIG_DEBUG_SLAB
Fix kzalloc() and kstrdup() caller report for CONFIG_DEBUG_SLAB.  We must
pass the caller to __cache_alloc() instead of directly doing
__builtin_return_address(0) there; otherwise kzalloc() and kstrdup() are
reported as the allocation site instead of the real one.

Thanks to Valdis Kletnieks for reporting the problem and Steven Rostedt for
the original idea.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:18 -08:00
Andrew Morton
b958f7d9f3 [PATCH] dump_stack() in oom handler
Sometimes it's nice to know who's calling.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:18 -08:00
Pekka Enberg
343e0d7a93 [PATCH] slab: replace kmem_cache_t with struct kmem_cache
Replace uses of kmem_cache_t with proper struct kmem_cache in mm/slab.c.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:18 -08:00
Pekka Enberg
9a2dba4b49 [PATCH] slab: rename ac_data to cpu_cache_get
Rename the ac_data() function to more descriptive cpu_cache_get().

Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:18 -08:00
Pekka Enberg
6ed5eb2211 [PATCH] slab: extract virt_to_{cache|slab}
Introduce virt_to_cache() and virt_to_slab() functions to reduce duplicate
code and introduce a proper abstraction should we want to support other kind
of mapping for address to slab and cache (eg.  for vmalloc() or I/O memory).

Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:18 -08:00
Pekka Enberg
5295a74cc0 [PATCH] slab: reduce inlining
From: Manfred Spraul <manfred@colorfullife.com>

Reduce the amount of inline functions in slab to the functions that
are used in the hot path:

  - no inline for debug functions
  - no __always_inline, inline is already __always_inline
  - remove inline from a few numa support functions.

Before:

   text    data     bss     dec     hex filename
  13588     752      48   14388    3834 mm/slab.o (defconfig)
  16671    2492      48   19211    4b0b mm/slab.o (numa)

After:

   text    data     bss     dec     hex filename
  13366     752      48   14166    3756 mm/slab.o (defconfig)
  16230    2492      48   18770    4952 mm/slab.o (numa)

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Matthew Dobson
78d382d77c [PATCH] slab: extract slab_{put|get}_obj
Create two helper functions slab_get_obj() and slab_put_obj() to replace
duplicated code in mm/slab.c

Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Matthew Dobson
12dd36faec [PATCH] slab: extract slab_destroy_objs()
Create a helper function, slab_destroy_objs() which called from
slab_destroy().  This makes slab_destroy() smaller and more readable, and
moves ifdefs outside the function body.

Signed-off-by: Matthew Dobson <colpatch@us.ibm.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Steven Rostedt
fbaccacff1 [PATCH] slab: cache_estimate cleanup
Clean up cache_estimate() in mm/slab.c and improves the algorithm from O(n) to
O(1).  We first calculate the maximum number of objects a slab can hold after
struct slab and kmem_bufctl_t for each object has been given enough space.
After that, to respect alignment rules, we decrease the number of objects if
necessary.  As required padding is at most align-1 and memory of obj_size is
at least align, it is always enough to decrease number of objects by one.

The optimization was originally made by Balbir Singh with more improvements
from Steven Rostedt.  Manfred Spraul provider further modifications: no loop
at all for the off-slab case and added comments to explain the background.

Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Steven Rostedt
5ec8a847bb [PATCH] slab: have index_of bug at compile time
I noticed the code for index_of is a creative way of finding the cache
index using the compiler to optimize to a single hard coded number.  But
I couldn't help noticing that it uses two methods to let you know that
someone used it wrong.  One is at compile time (the correct way), and
the other is at run time (not good).

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Christoph Lameter
18f820f655 [PATCH] slab: minor cleanup to kmem_cache_alloc_node
Clean up kmem_cache_alloc_node a bit.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Manfred Spraul
3dafccf227 [PATCH] slab: distinguish between object and buffer size
An object cache has two different object lengths:

  - the amount of memory available for the user (object size)
  - the amount of memory allocated internally (buffer size)

This patch does some renames to make the code reflect that better.

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Christoph Lameter
e965f9630c [PATCH] Direct Migration V9: Avoid writeback / page_migrate() method
Migrate a page with buffers without requiring writeback

This introduces a new address space operation migratepage() that may be used
by a filesystem to implement its own version of page migration.

A version is provided that migrates buffers attached to pages.  Some
filesystems (ext2, ext3, xfs) are modified to utilize this feature.

The swapper address space operation are modified so that a regular
migrate_page() will occur for anonymous pages without writeback (migrate_pages
forces every anonymous page to have a swap entry).

Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:17 -08:00
Christoph Lameter
7e2ab150d1 [PATCH] Direct Migration V9: upgrade MPOL_MF_MOVE and sys_migrate_pages()
Modify policy layer to support direct page migration

- Add migrate_pages_to() allowing the migration of a list of pages to a a
  specified node or to vma with a specific allocation policy in sets of
  MIGRATE_CHUNK_SIZE pages

- Modify do_migrate_pages() to do a staged move of pages from the source
  nodes to the target nodes.

Signed-off-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
a3351e525e [PATCH] Direct Migration V9: remove_from_swap() to remove swap ptes
Add remove_from_swap

remove_from_swap() allows the restoration of the pte entries that existed
before page migration occurred for anonymous pages by walking the reverse
maps.  This reduces swap use and establishes regular pte's without the need
for page faults.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
a48d07afdf [PATCH] Direct Migration V9: migrate_pages() extension
Add direct migration support with fall back to swap.

Direct migration support on top of the swap based page migration facility.

This allows the direct migration of anonymous pages and the migration of file
backed pages by dropping the associated buffers (requires writeout).

Fall back to swap out if necessary.

The patch is based on lots of patches from the hotplug project but the code
was restructured, documented and simplified as much as possible.

Note that an additional patch that defines the migrate_page() method for
filesystems is necessary in order to avoid writeback for anonymous and file
backed pages.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Mike Kravetz <kravetz@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
b16664e44c [PATCH] Direct Migration V9: PageSwapCache checks
Check for PageSwapCache after looking up and locking a swap page.

The page migration code may change a swap pte to point to a different page
under lock_page().

If that happens then the vm must retry the lookup operation in the swap space
to find the correct page number.  There are a couple of locations in the VM
where a lock_page() is done on a swap page.  In these locations we need to
check afterwards if the page was migrated.  If the page was migrated then the
old page that was looked up before was freed and no longer has the
PageSwapCache bit set.

Signed-off-by: Hirokazu Takahashi <taka@valinux.co.jp>
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Christoph Lameter <clameter@@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
2a16e3f4b0 [PATCH] Reclaim slab during zone reclaim
If large amounts of zone memory are used by empty slabs then zone_reclaim
becomes uneffective.  This patch shakes the slab a bit.

The problem with this patch is that the slab reclaim is not containable to a
zone.  Thus slab reclaim may affect the whole system and be extremely slow.
This also means that we cannot determine how many pages were freed in this
zone.  Thus we need to go off node for at least one allocation.

The functionality is disabled by default.

We could modify the shrinkers to take a zone parameter but that would be quite
invasive.  Better ideas are welcome.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
1b2ffb7896 [PATCH] Zone reclaim: Allow modification of zone reclaim behavior
In some situations one may want zone_reclaim to behave differently.  For
example a process writing large amounts of memory will spew unto other nodes
to cache the writes if many pages in a zone become dirty.  This may impact the
performance of processes running on other nodes.

Allowing writes during reclaim puts a stop to that behavior and throttles the
process by restricting the pages to the local zone.

Similarly one may want to contain processes to local memory by enabling
regular swap behavior during zone_reclaim.  Off node memory allocation can
then be controlled through memory policies and cpusets.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
2a11ff06d7 [PATCH] zone_reclaim: configurable off node allocation period.
Currently the zone_reclaim code has a fixed window of 30 seconds of off node
allocations should a local zone have no unused pagecache pages left.  Reclaim
will be attempted again after this timeout period to avoid repeated useless
scans for memory.  This is also useful to established sufficiently large off
node allocation chunks to relieve the local node.

It may be beneficial to adjust that time period for some special situations.
For example if memory use was exceeding node capacity one may want to give up
for longer periods of time.  If memory spikes intermittendly then one may want
to shorten the time period to reduce the number of off node allocations.

This patch allows just that....

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
a92f71263a [PATCH] zone_reclaim: partial scans instead of full scan
Instead of scanning all the pages in a zone, imitate real swap and scan
only a portion of the pages and gradually scan more if we do not free up
enough pages.  This avoids a zone suddenly loosing all unused pagecache
pages (we may after all access some of these again so they deserve another
chance) but it still frees up large chunks of memory if a zone only
contains unused pagecache pages.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:16 -08:00
Christoph Lameter
aa3f18b339 [PATCH] zone_reclaim: do not unmap file backed pages
zone_reclaim should leave that to the real swapper.  We are only interested
in evicting unmapped pages.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:15 -08:00
Benjamin LaHaise
9884fd8df1 [PATCH] Use 32 bit division in slab_put_obj()
Improve the performance of slab_put_obj().  Without the cast, gcc considers
ptrdiff_t a 64 bit signed integer and ends up emitting code to use a full
signed 128 bit divide on EM64T, which is substantially slower than a 32 bit
unsigned divide.

I noticed this when looking at the profile of a case where the slab balance
is just on edge and thrashes back and forth freeing a block.

Signed-off-by: Benjamin LaHaise <benjamin.c.lahaise@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:15 -08:00
Christoph Lameter
c84db23c6e [PATCH] zone_reclaim: minor fixes
- If we only reclaim nr_pages then its okay to stay on node.
  Switch from > to >= for the comparison.

- vm_table[] entry for zone_reclaim_mode is a bit screwed up.

- Add empty lines around shrink_zone to show that this is the
  central function to be called.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:15 -08:00
Christoph Lameter
52a8363eae [PATCH] mm: improve function of sc->may_writepage
Make sc->may_writepage control the writeout behavior of shrink_list.

Remove the laptop_mode trick from shrink_list and instead set may_writepage
in try_to_free_pages properly.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:15 -08:00
Christoph Lameter
42c722d4cb [PATCH] zone_reclaim: reclaim on memory only node support
Zone reclaim is usually only run on the local node.  Headless nodes do not
have any local processors.  This patch checks for headless nodes and
performs zone reclaim on them.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:14 -08:00
Christoph Lameter
8928862398 [PATCH] Optimize off-node performance of zone reclaim
Ensure that the performance of off node pages stays the same as before.
Off node pagefault tests showed an 18% drop in performance without this
patch.

- Increase the timeout to 30 seconds to reduce the overhead.

- Move all code possible out of the off node hot path for zone reclaim
  (Sorry Andrew, the struct initialization had to be sacrificed).
  The read_page_state() bit us there.

- Check first for the timeout before any other checks.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:14 -08:00
Ashok Raj
6292d9aaf3 [PATCH] __cpuinit functions wrongly marked __meminit
__meminit has overzelously been modified and crept its way into marking
cpuup callbacks as __meminit.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-01 08:53:09 -08:00
Christoph Lameter
86c562a9d6 [PATCH] mm: optimize numa policy handling in slab allocator
Move the interrupt check from slab_node into ___cache_alloc and adds an
"unlikely()" to avoid pipeline stalls on some architectures.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:18 -08:00