Date: Wed, 4 Aug 2004 17:32:36 -0400 From: Brian Fundakowski Feldman <green@FreeBSD.org> To: John Baldwin <jhb@FreeBSD.org> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/i386/i386 pmap.c src/sys/kern subr_witness.c Message-ID: <20040804213236.GA58239@green.homeunix.org> In-Reply-To: <200408041634.03998.jhb@FreeBSD.org> References: <200408042031.i74KVKUf039025@repoman.freebsd.org> <200408041634.03998.jhb@FreeBSD.org>
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On Wed, Aug 04, 2004 at 04:34:03PM -0400, John Baldwin wrote: > On Wednesday 04 August 2004 04:31 pm, John Baldwin wrote: > > jhb 2004-08-04 20:31:19 UTC > > > > FreeBSD src repository > > > > Modified files: > > sys/i386/i386 pmap.c > > sys/kern subr_witness.c > > Log: > > Remove a potential deadlock on i386 SMP by changing the lazypmap ipi and > > spin-wait code to use the same spin mutex (smp_tlb_mtx) as the TLB ipi > > and spin-wait code snippets so that you can't get into the situation of > > one CPU doing a TLB shootdown to another CPU that is doing a lazy pmap > > shootdown each of which are waiting on each other. With this change, > > only one of the CPUs would do an IPI and spin-wait at a time. > > Both this patch and the previous I have tested locally and also sent out to > current@ for testing. However, I received zero feedback (not even useless > feedback), so they may theoretically be risky. "No feedback is good feedback" -- those changes have caused no problems for me during non-PREEMPTION-only testing on my dual Athlon. -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\
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