Messages in this thread | | | Date | Wed, 02 Feb 2011 14:24:58 +0530 | From | Ciju Rajan K <> | Subject | Re: [PATCH 1/2 v2.0]sched: Removing unused fields from /proc/schedstat |
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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
[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
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