[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Old Index]
Re: kern/45093: kernel deadlock between TCP and UVM involving callouts
The following reply was made to PR kern/45093; it has been noted by GNATS.
From: David Holland <dholland-bugs%netbsd.org@localhost>
Subject: Re: kern/45093: kernel deadlock between TCP and UVM involving
Date: Wed, 20 Jul 2011 07:07:45 +0000
For some reason this didn't go to gnats even though it contains the PR
number in what I think is supposed to be a recognized format.
From: Manuel Bouyer <bouyer%netbsd.org@localhost>
Subject: CVS commit: src/sys
Date: Sat, 2 Jul 2011 17:53:51 +0000
Module Name: src
Committed By: bouyer
Date: Sat Jul 2 17:53:51 UTC 2011
src/sys/kern: init_main.c uipc_socket.c
Fix kern/45093 as discussed on tech-kern@:
The cause of the problem is that the so_pendfree is processed with
the softnet_lock held at one point, and processing the list
calls sodoloanfree() which may kpause(). As the thread sleeps with
softnet_lock held, it ultimately cause a deadlock (see the PR or tech-kern
thread for details).
Although it should be possible to call sodopendfree() after releasing
the socket lock, it's not so easy to know where he socket lock is held and
where it's not, so we may hit the issue again later.
Add a kernel thread to handle the so_pendfree list, and wake up this
thread when adding mbufs to this list. Get rid of the various sodopendfree()
calls, hopefully fixing definitively the problem.
To generate a diff of this commit:
cvs rdiff -u -r1.432 -r1.433 src/sys/kern/init_main.c
cvs rdiff -u -r1.204 -r1.205 src/sys/kern/uipc_socket.c
cvs rdiff -u -r1.125 -r1.126 src/sys/sys/socketvar.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Main Index |
Thread Index |