Messages in this thread | | | Date | Fri, 10 Oct 2008 15:31:00 +0400 | From | Evgeniy Polyakov <> | Subject | Re: [tbench regression fixes]: digging out smelly deadmen. |
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Hi Ingo.
On Fri, Oct 10, 2008 at 11:15:11AM +0200, Ingo Molnar (mingo@elte.hu) wrote:
> > > > I use tsc clocksource, also available acpi_pm and jiffies, > > with acpi_pm performance is even lower (I stopped test after it dropped > > below 340 MB/s mark), jiffies do not work at all, looks like sockets > > stuck in time_wait state when this clock source is used, although that > > may be some different issue. > > > > So I think hrticks are guilty, but still not as good as .25 tree without > > mentioned changes (455 MB/s) and .24 (475 MB/s). > > i'm glad that you are looking into this! That is an SMP box, right? If > yes then could you try this sched-domains tuning utility i have written > yesterday (incidentally): > > http://redhat.com/~mingo/cfs-scheduler/tune-sched-domains
I've removed SD_BALANCE_NEWIDLE: # ./tune-sched-domains $[191-2] changed /proc/sys/kernel/sched_domain/cpu0/domain0/flags: 191 => 189 SD flag: 189 + 1: SD_LOAD_BALANCE: Do load balancing on this domain - 2: SD_BALANCE_NEWIDLE: Balance when about to become idle + 4: SD_BALANCE_EXEC: Balance on exec + 8: SD_BALANCE_FORK: Balance on fork, clone + 16: SD_WAKE_IDLE: Wake to idle CPU on task wakeup + 32: SD_WAKE_AFFINE: Wake task to waking CPU - 64: SD_WAKE_BALANCE: Perform balancing at task wakeup + 128: SD_SHARE_CPUPOWER: Domain members share cpu power changed /proc/sys/kernel/sched_domain/cpu0/domain1/flags: 47 => 189 SD flag: 189 + 1: SD_LOAD_BALANCE: Do load balancing on this domain - 2: SD_BALANCE_NEWIDLE: Balance when about to become idle + 4: SD_BALANCE_EXEC: Balance on exec + 8: SD_BALANCE_FORK: Balance on fork, clone + 16: SD_WAKE_IDLE: Wake to idle CPU on task wakeup + 32: SD_WAKE_AFFINE: Wake task to waking CPU - 64: SD_WAKE_BALANCE: Perform balancing at task wakeup + 128: SD_SHARE_CPUPOWER: Domain members share cpu power
And got noticeble improvement (each new line has fixes from previous):
vanilla 27: 347.222 no TSO/GSO: 357.331 no hrticks: 382.983 no balance: 389.802
> and please, when tuning such scheduler bits, could you run latest > tip/master: > > http://people.redhat.com/mingo/tip.git/README > > and you need to have CONFIG_SCHED_DEBUG=y enabled for the tuning knobs. > > so that it's all in sync with upcoming scheduler changes/tunings/fixes.
Ok, I've started to pull it down, I will reply back when things are ready.
-- Evgeniy Polyakov
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