Messages in this thread | | | From | Frederic Weisbecker <> | Subject | [RFC PATCH 0/5] nohz: Fix racy sleeptime stats v2 | Date | Sat, 19 Oct 2013 17:17:16 +0200 |
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Hi,
So this is a new iteration with some more changes on top of the latest discussions we had.
Unfortunately it's not yet a real viable solution. Check out patch 4/5 for details, I think that's too much overhead. Also it changes enough the semantics to break the idle sleeptime accounting along the way. This is because moving the accounting to io_schedule() makes it account _all_ IO sleeptime, even if the CPU is still busy, not just when it is idle like before. As a result, the idle sleeptime, that relies on a diff against the io sleeptime, is broken.
Anyway, my hope with this new take is mostly to launch a discussion with a fresher base and see if we can find better ideas.
Thanks!
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git sched/iowait
Thanks, Frederic ---
Frederic Weisbecker (5): nohz: Convert a few places to use local per cpu accesses nohz: Only update sleeptime stats locally timer: Change idle/iowait accounting semantics sched: Refactor iowait accounting nohz: Synchronize sleep time stats with seqlock
include/linux/ktime.h | 7 +++ include/linux/sched.h | 1 + include/linux/tick.h | 11 ++-- kernel/sched/core.c | 68 ++++++++++++++++++--- kernel/sched/cputime.c | 2 +- kernel/sched/sched.h | 5 +- kernel/softirq.c | 4 +- kernel/time/tick-broadcast.c | 6 +- kernel/time/tick-internal.h | 4 +- kernel/time/tick-sched.c | 138 ++++++++++++++----------------------------- kernel/time/timer_list.c | 3 +- 11 files changed, 130 insertions(+), 119 deletions(-)
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