Date: Wed, 14 Aug 2002 01:49:06 -0700 From: Terry Lambert <tlambert2@mindspring.com> To: sjh@ucf.ics.uci.edu Cc: current@freebsd.org Subject: Re: bremfree: bp 0xc77938f4 not locked (Most recently used by kqueue) Message-ID: <3D5A1982.87B8C015@mindspring.com> References: <200208130533.g7D5Xql13446@whiskey.ucf.ics.uci.edu>
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Seth Hettich wrote: > I get this all the time, and have for months now. On two different > systems (both updated to -current about 2 times per month), both > PCs (but with greatly differing HW). > > What would be my first step to resolve this? I sent in a PR, with > lots of notes, things I tried, and stack dumps. I'm willing to do > some more work on it, if someone can point me in the right direction. > > panic: bremfree: bp 0xc77938f4 not locked > panic messages: > --- > panic: Most recently used by kqueue Having just finished documenting all of the kqueue code internals for my own use, I can tell you exactly where this problem lies. If you look at the kqueue code itself, in /sys/kern/kern_event.c, you will see the function knote(). The knote() function is conceptually very simple; it iterates the knote list hung off an object on which an event has just occurred, and calls the function kn->kn_fop->f_event(kn, hint). If you remember Julian's recent commit to the queue.h to make the list iterators unsafe to do removes in (OK, technically, he didn't make the change for that, it was just a very important undesirable side effect 8-)), you will understand the problem. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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