Date: Thu, 24 Sep 1998 04:49:22 -0700 From: Don Lewis <Don.Lewis@tsc.tdk.com> To: Alexander Litvin <archer@lucky.net>, Luoqi Chen <luoqi@watermarkgroup.com> Cc: current@FreeBSD.ORG Subject: Re: deadlock in vm_fault() Message-ID: <199809241149.EAA24754@salsa.gv.tsc.tdk.com> In-Reply-To: Alexander Litvin <archer@lucky.net> "Re: deadlock in vm_fault()" (Sep 24, 1:05pm)
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On Sep 24, 1:05pm, Alexander Litvin wrote: } Subject: Re: deadlock in vm_fault() } In article <199809232224.SAA17260@lor.watermarkgroup.com> you wrote: } LC> I ran into a deadlock in vm_fault code today while making -j12 world. } LC> It's caused by a reversed lock acquisition order. The normal order of } LC> acquisition is vm map lock first and vnode lock next (if the fault is in } LC> a vnode backed object). During the course of the fault handling, lock on } LC> the vm map is released prior to paging io and has to be reacquired if it's } LC> modified by another process during the io. Before reacquiring the lock of } LC> vm map, we have to release the vnode lock we still hold, otherwise another } LC> page fault in the same map/vnode would send us into a deadlock. } } LC> Attached is a fix for this problem. Would any of the vm/lock experts out } LC> there review this? Thanks. } } I've seen something strange during the same -j12 buildworld. In fact, } it was just that ld hang, apparently not doing anything. The rest } of the system seemed to be alive. Though in some 3 or 4 hours machine } rebooted (it had kernel with broken crash dump generation, so I do } not know what actually happened). } } May it be related? Sounds likely. I've seen something else with -j12 (but not -j11 or lower). I don't have any particular reason to suspect the kernel on this one, but it is an interesting coincidence. --- config_h.sh --- cp -p /usr/src/gnu/usr.bin/perl/suidperl/../../../../contrib/perl5/config_h.SH config_h.sh --- config.sh --- cp -p /usr/src/gnu/usr.bin/perl/suidperl/../libperl/config.SH-elf.i386 config.sh --- cflags.sh --- cp -p /usr/src/gnu/usr.bin/perl/suidperl/../../../../contrib/perl5/cflags.SH cflags.sh --- writemain.sh --- --- myconfig --- --- writemain --- sh writemain.sh Extracting writemain (with variable substitutions) writemain: not found *** Error code 127 1 error *** Error code 2 1 error *** Error code 2 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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