Messages in this thread |  | | | Date | Thu, 03 Feb 2011 18:19:26 +0900 | | From | Satoru Takeuchi <> | | Subject | Re: [PATCH 1/2 v2.0]sched: Removing unused fields from /proc/schedstat |
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Hi Ciju,
(2011/02/02 17:54), Ciju Rajan K wrote: > Hi Satoru, > > >>> I think we can remove rq->sched_switch and rq->sched_switch >>> without no problem because they are meaningless. The former >>> is for old O(1) scheduler and means the number of runqueue >>> switching among active/expired queue. The latter is for >>> SD_WAKE_BALANCE flag and its logic is already gone. >>> >>> However sbe_* are for SD_BALANCE_EXEC flag and sbf_* are for >>> SD_BALANCE_FORK flag. Since both logic for them are still alive, >>> the absence of these accounting is regression in my perspective. >>> In addition, these fields would be useful for analyzing load >>> balance behavior. >>> > > The sbe_*& sbf_* counters were added by the commit > 68767a0ae428801649d510d9a65bb71feed44dd1 But it was subsequently > removed by the commit 476d139c218e44e045e4bc6d4cc02b010b343939
OK, I understood. It's OK if user tools referring /proc/schedstat are released sync with this change.
I confirmed the following:
- This patch removes some unused schedstat fields and related data. - The kernel applying this patch works fine on my i386 box.
Tested-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com>
Thanks, Satoru
> > [ciju@ciju kernel]$ git describe 68767a0ae428801649d510d9a65bb71feed44dd1 --contains > v2.6.13-rc1~68^2~148 > [ciju@ciju kernel]$ git describe 476d139c218e44e045e4bc6d4cc02b010b343939 --contains > v2.6.13-rc1~68^2~140 > > So.. it was introduced and removed in 2.6.13 time frame > > > When the counters were removed the sbe_* sbf_* variable > declarations were not removed. Hence it caused a little confusion. > So I believe these stats were not available and hence can't be > considered as regression. > > 476d139c218e44e045e4bc6d4cc02b010b343939 consolidated the fork and > exec balance. Thereafter it became non-trivial to provide separate > stats for fork and exec events. So if people think a consolidated > balance-on-event is needed, it can be looked into separately. But > that shouldn't prevent this documentation cleanup patch from > getting in. > > -Ciju > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > >
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