]> err.no Git - linux-2.6/commit
[PATCH] Prefetch kernel stacks to speed up context switch
authorChen, Kenneth W <kenneth.w.chen@intel.com>
Fri, 9 Sep 2005 20:02:02 +0000 (13:02 -0700)
committerLinus Torvalds <torvalds@g5.osdl.org>
Fri, 9 Sep 2005 20:57:31 +0000 (13:57 -0700)
commit383f2835eb9afb723af71850037b2f074ac9db60
tree1ef99fd4d7246b2afa16dc7d1514b6ff25fa8284
parentb0d62e6d5b3318b6b722121d945afa295f7201b5
[PATCH] Prefetch kernel stacks to speed up context switch

For architecture like ia64, the switch stack structure is fairly large
(currently 528 bytes).  For context switch intensive application, we found
that significant amount of cache misses occurs in switch_to() function.
The following patch adds a hook in the schedule() function to prefetch
switch stack structure as soon as 'next' task is determined.  This allows
maximum overlap in prefetch cache lines for that structure.

Signed-off-by: Ken Chen <kenneth.w.chen@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arch/ia64/kernel/entry.S
include/asm-ia64/system.h
include/linux/sched.h
kernel/sched.c