Date: Wed, 11 Aug 2010 19:25:45 +0200 From: Attilio Rao <attilio@freebsd.org> To: John Baldwin <jhb@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r211176 - in head/sys: amd64/amd64 i386/i386 Message-ID: <AANLkTimczmkAkqTnCDmHh1otsX1OuVggeEA8NkpY3bYO@mail.gmail.com> In-Reply-To: <4C62DADF.1000202@FreeBSD.org> References: <201008111051.o7BApRp4028538@svn.freebsd.org> <4C62DADF.1000202@FreeBSD.org>
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2010/8/11 John Baldwin <jhb@freebsd.org>: > Attilio Rao wrote: >> >> Author: attilio >> Date: Wed Aug 11 10:51:27 2010 >> New Revision: 211176 >> URL: http://svn.freebsd.org/changeset/base/211176 >> >> Log: >> =C2=A0IPI handlers may run generally with interrupts disabled because th= ey >> =C2=A0are served via an interrupt gate. >> =C2=A0 =C2=A0However, that doesn't explicitly prevent preemption and thr= ead >> =C2=A0migration thus scheduler pinning may be necessary in some handlers= . >> =C2=A0Fix that. >> =C2=A0 =C2=A0Tested by: =C2=A0gianni >> =C2=A0MFC after: =C2=A0 =C2=A01 month > > Actually that does prevent preemption if you do not call any code that wo= uld > schedule a thread. =C2=A0I think this change is all safe to revert. Do you recall, then, why lapic_handle_timer() does critical section? It seems to be catered by interrupt gate as well, and I don't see any point re-enabling them explicitly. Thanks, Attilio --=20 Peace can only be achieved by understanding - A. Einstein
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