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| author | Paul Jackson <pj@sgi.com> | 2006-12-06 20:31:49 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-07 08:39:20 -0800 |
| commit | 7253f4ef04b1cd138baf2b29a95473743ac0a307 (patch) | |
| tree | 5883e6773a3cdad31992539ba3ad989d2566a041 /include/linux/mmzone.h | |
| parent | 9276b1bc96a132f4068fdee00983c532f43d3a26 (diff) | |
| download | lwn-7253f4ef04b1cd138baf2b29a95473743ac0a307.tar.gz lwn-7253f4ef04b1cd138baf2b29a95473743ac0a307.zip | |
[PATCH] memory page_alloc zonelist caching reorder structure
Rearrange the struct members in the 'struct zonelist_cache' structure, so
as to put the readonly (once initialized) z_to_n[] array first, where it
will come right after the zones[] array in struct zonelist.
This pretty much eliminates the chance that the two frequently written
elements of 'struct zonelist_cache', the fullzones bitmap and last_full_zap
times, will end up on the same cache line as the performance sensitive,
frequently read, never (after init) written zones[] array.
Keeping frequently written data off frequently read cache lines is good for
performance.
Thanks to Rohit Seth for the suggestion.
Signed-off-by: Paul Jackson <pj@sgi.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/mmzone.h')
| -rw-r--r-- | include/linux/mmzone.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 09bf9d8d7b72..da6002dec205 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -352,8 +352,8 @@ struct zone { struct zonelist_cache { - DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */ unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */ + DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */ unsigned long last_full_zap; /* when last zap'd (jiffies) */ }; #else |