| commit | b2d9323d139f5c384fa1ef1d74773b4db1c09b3d | |
| author | john stultz <johnstul@us.ibm.com> | |
| Wed, 17 Oct 2007 06:27:18 +0000 (16 23:27 -0700) | ||
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | |
| Wed, 17 Oct 2007 15:42:53 +0000 (17 08:42 -0700) | ||
| tree | ad2705044b5b781aeb1a119d9c8548a044c7e21f | treesnapshot (tar.gz zip) |
| parent | 3075d9da0b4ccc88959db30de80ebd11d2dde175 | commitdiff |
Use num_possible_cpus() instead of NR_CPUS for timer distribution
To avoid lock contention, we distribute the sched_timer calls across the
cpus so they do not trigger at the same instant. However, I used NR_CPUS,
which can cause needless grouping on small smp systems depending on your
kernel config. This patch converts to using num_possible_cpus() so we
spread it as evenly as possible on every machine.
Briefly tested w/ NR_CPUS=255 and verified reduced contention.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To avoid lock contention, we distribute the sched_timer calls across the
cpus so they do not trigger at the same instant. However, I used NR_CPUS,
which can cause needless grouping on small smp systems depending on your
kernel config. This patch converts to using num_possible_cpus() so we
spread it as evenly as possible on every machine.
Briefly tested w/ NR_CPUS=255 and verified reduced contention.
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| kernel/time/tick-sched.c | diffblobblamehistory |