JFS: performance patch

Basically, we saw a large amount of time spent in the
jfs_strfromUCS_le() function, mispredicting the branch inside the
loop, so I just added some unlikely modifiers to the if statements to
re-ordered the code.  Again, these simple changes provided > 2 % on
spec-sfs, so please consider it for inclusion.

Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
This commit is contained in:
Sonny Rao 2005-06-23 16:57:56 -05:00 committed by Dave Kleikamp
parent a8ad86f2dc
commit f5f287738b

View File

@ -51,8 +51,9 @@ int jfs_strfromUCS_le(char *to, const __le16 * from,
}
} else {
for (i = 0; (i < len) && from[i]; i++) {
if (le16_to_cpu(from[i]) & 0xff00) {
if (warn) {
if (unlikely(le16_to_cpu(from[i]) & 0xff00)) {
to[i] = '?';
if (unlikely(warn)) {
warn--;
warn_again--;
printk(KERN_ERR
@ -61,7 +62,7 @@ int jfs_strfromUCS_le(char *to, const __le16 * from,
printk(KERN_ERR
"mount with iocharset=utf8 to access\n");
}
to[i] = '?';
}
else
to[i] = (char) (le16_to_cpu(from[i]));