Date: Sun, 07 Jul 2002 14:18:16 -0700 From: Peter Wemm <peter@wemm.org> To: Luigi Rizzo <rizzo@icir.org> Cc: Alan Cox <alc@FreeBSD.ORG>, cvs-committers@FreeBSD.ORG, cvs-all@FreeBSD.ORG Subject: Re: cvs commit: src/sys/vm vm_zeroidle.c Message-ID: <20020707211816.C7EF13808@overcee.wemm.org> In-Reply-To: <20020707140210.A64548@iguana.icir.org>
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Luigi Rizzo wrote: > While you are on this file: there is a rather tricky bug > in the priority of the process. > > It starts at RTP_PRIO_IDLE, but after the first tsleep > its priority gets raised to PPAUSE (which is much higher) > and never gets reset to the proper value. > > The effect is that the process runs with very high priority, > and the only reason you don't notice (or maybe you do) is > that after a while the process does not have any more > pages to zero and voluntarily deschedules. > > For a fix (rather trivial) have a look at > > sys/kern/kern_poll.c:poll_idle() > > which does not have the nice property of descheduling > itself and so makes the bug quite evident. Eww. Yes, the act of resetting an elevated priority at the return transition to userland would be a problem here. I know Bruce has a huge list of things he has changed here as well. I was going for baby steps to make it usable again. > cheers > luigi > > On Sun, Jul 07, 2002 at 12:27:57PM -0700, Alan Cox wrote: > > alc 2002/07/07 12:27:57 PDT > > > > Modified files: > > sys/vm vm_zeroidle.c > > Log: > > o Lock accesses to the free queue(s) in vm_page_zero_idle(). > > > > Revision Changes Path > > 1.10 +4 -0 src/sys/vm/vm_zeroidle.c > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe cvs-all" in the body of the message > Cheers, -Peter -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com "All of this is for nothing if we don't go to the stars" - JMS/B5 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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