diff options
| 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 /arch/alpha/lib/divide.S | |
| parent | 0a9ac38246b11892ad20a1eb9deb67adf8c0db2f (diff) | |
[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 'arch/alpha/lib/divide.S')
0 files changed, 0 insertions, 0 deletions