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| author |   Nick Piggin <npiggin@suse.de> | 2007-02-12 00:53:51 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-12 09:48:37 -0800 |
| commit | ff91691bccdb741efb2df0489058a4961fa79598 (patch) | |
| tree | eeef6ce3d48df86a7b2c1178a9ba54210b8b8981 /init/main.c | |
| parent | [PATCH] eCryptfs: add flush_dcache_page() calls (diff) | |
| download | linux-dev-ff91691bccdb741efb2df0489058a4961fa79598.tar.xz linux-dev-ff91691bccdb741efb2df0489058a4961fa79598.zip | |
[PATCH] sched: avoid div in rebalance_tick
Avoid expensive integer divide 3 times per CPU per tick.
A userspace test of this loop went from 26ns, down to 19ns on a G5; and
from 123ns down to 28ns on a P3.
(Also avoid a variable bit shift, as suggested by Alan. The effect
of this wasn't noticable on the CPUs I tested with).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
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>
Diffstat (limited to 'init/main.c')
0 files changed, 0 insertions, 0 deletions