Messages in this thread | | | Date | Mon, 10 Mar 2008 14:07:12 -0700 | From | Hiroshi Shimamoto <> | Subject | Re: [PATCH] sched: fix race in schedule |
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Peter Zijlstra wrote: > On Mon, 2008-03-10 at 13:54 -0700, Hiroshi Shimamoto wrote: >> Peter Zijlstra wrote: >>> On Mon, 2008-03-10 at 13:01 -0700, Hiroshi Shimamoto wrote: >>> >>>> thanks, your patch looks nice to me. >>>> I had focused setprio, on_rq=0 and running=1 situation, it makes me to >>>> fix these functions. >>>> But one point, I've just noticed. I'm not sure on same situation against >>>> sched_rt. I think the pre_schedule() of rt has chance to drop rq lock. >>>> Is it OK? >>> Ah, you are quite right, that'll teach me to rush out a patch just >>> because dinner is ready :-). >>> >>> How about we submit the following patch for mainline and CC -stable to >>> fix .23 and .24: >> thanks for working, I'm OK, and will test it soon. >> IIRC, it came from the group scheduling, .23 probably doesn't have this issue. > > Might not have this exact race, but I've checked both .23 and .24, both > can unlock the rq before we do ->put_prev_task(), leaving a window for > potential nasties. I'm rather safe than sorry :-)
Ah, you're correct. I haven't gotten out from the first situation yet :-)
thanks, Hiroshi Shimamoto
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