Date: Mon, 08 Jan 2001 17:41:35 -0800 (PST) From: John Baldwin <jhb@FreeBSD.org> To: Robert Lipe <robertlipe@usa.net> Cc: freebsd-hackers@FreeBSD.org Subject: Re: kthread_exit & zombification Message-ID: <XFMail.010108174135.jhb@FreeBSD.org> In-Reply-To: <20010108184732.N1400@rjlhome.sco.com>
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On 09-Jan-01 Robert Lipe wrote: > John Baldwin wrote: >> >> On 08-Jan-01 Robert Lipe wrote: > >> > I'm having problems with kthread_exit(). The problem is that the thread >> > goes zombie after I kthread_exit in it, but it never gets reaped. Since >> > I'm doing this during a MOD_UNLOAD phase, if I happen to do a `ps -ax' >> > after the module has been unmapped, a panic results becuase it's trying >> > to get the lwp name and wchan string from what is now unmapped memory. >> >> kthreads are children of the swapper (pid 0), which doesn't harvest zombies. > > Bummer. I can get past the zombies as they're merely unsightly. Panics > are a drag. :-) Unloading modules adds all sorts of new problems. Right now the WITNESS code will do bad bad things if you kldunload a module that contains a mutex. Even if the mutex is mtx_destroy'd because it still has a reference to its name in the internal lists it keeps. >> Hmm, a fix was committed to kthread_exit() in -current in rev 1.8 of >> sys/kern/kern_kthread.c. Actually, if you could test out both rev 1.8 and >> 1.9 >> that would be good, as both need to be backported to -stable. > > Only 1.8 seems to be be pertinent to 4.1.1. I've stitched in the call > to proc_reparent() and life seems pretty good. `ps' no longer panics > and the lwp does indeed disappear from the ps listing instead of merely > going zombie. This doesn't quite seem to jive with what you described > above, though. By reparenting to init, the zombie is harvested isntead of lying around. Now I just need to MFC this. > Thanx! > RJL -- John Baldwin <jhb@FreeBSD.org> -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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