Date: Fri, 5 Dec 2008 20:50:24 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/kern kern_exec.c kern_exit.c kern_fork.c kern_proc.c src/sys/sys proc.h Message-ID: <200812052051.mB5KpFEY043164@repoman.freebsd.org>
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kib 2008-12-05 20:50:24 UTC
FreeBSD src repository
Modified files:
sys/kern kern_exec.c kern_exit.c kern_fork.c
kern_proc.c
sys/sys proc.h
Log:
SVN rev 185647 on 2008-12-05 20:50:24Z by kib
Several threads in a process may do vfork() simultaneously. Then, all
parent threads sleep on the parent' struct proc until corresponding
child releases the vmspace. Each sleep is interlocked with proc mutex of
the child, that triggers assertion in the sleepq_add(). The assertion
requires that at any time, all simultaneous sleepers for the channel use
the same interlock.
Silent the assertion by using conditional variable allocated in the
child. Broadcast the variable event on exec() and exit().
Since struct proc * sleep wait channel is overloaded for several
unrelated events, I was unable to remove wakeups from the places where
cv_broadcast() is added, except exec().
Reported and tested by: ganbold
Suggested and reviewed by: jhb
MFC after: 2 week
Revision Changes Path
1.327 +1 -1 src/sys/kern/kern_exec.c
1.317 +2 -0 src/sys/kern/kern_exit.c
1.298 +1 -1 src/sys/kern/kern_fork.c
1.274 +1 -0 src/sys/kern/kern_proc.c
1.525 +2 -0 src/sys/sys/proc.h
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