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author | Andrew Morton <akpm@linux-foundation.org> | 2007-07-16 06:39:51 (GMT) |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-07-16 16:05:41 (GMT) |
commit | c67ad917cbf21b2862e2cf8e8b28339872ef7927 (patch) | |
tree | 362d8cf8668998b8cd5deb611693f584b8df5ee5 /fs | |
parent | 85420ccad1610f123365eec89848ef25641bc6b7 (diff) | |
download | linux-fsl-qoriq-c67ad917cbf21b2862e2cf8e8b28339872ef7927.tar.xz |
percpu_counters(): use cpu notifiers
per-cpu counters presently must iterate over all possible CPUs in the
exhaustive percpu_counter_sum().
But it can be much better to only iterate over the presently-online CPUs. To
do this, we must arrange for an offlined CPU's count to be spilled into the
counter's central count.
We can do this for all percpu_counters in the machine by linking them into a
single global list and walking that list at CPU_DEAD time.
(I hope. Might have race windows in which the percpu_counter_sum() count is
inaccurate?)
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
0 files changed, 0 insertions, 0 deletions