Date: Tue, 23 Jan 2001 09:23:12 -0800 (PST) From: John Baldwin <jhb@FreeBSD.ORG> To: Vallo Kallaste <vallo@matti.ee> Cc: cvs-all@FreeBSD.ORG, cvs-committers@FreeBSD.ORG, Alfred Perlstein <bright@wintelcom.net>, Bosko Milekic <bmilekic@technokratis.com> Subject: Re: cvs commit: src/sys/kern uipc_mbuf.c Message-ID: <XFMail.010123092312.jhb@FreeBSD.org> In-Reply-To: <20010123150639.A50085@myhakas.matti.ee>
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On 23-Jan-01 Vallo Kallaste wrote: > On Tue, Jan 16, 2001 at 07:37:05PM -0500, Bosko Milekic > <bmilekic@technokratis.com> wrote: > >> The discussed situation was probably a lock order reversal w.r.t. Giant and >> some driver lock (in an MP safe driver). In one case, as you mentionned, >> Giant can be acquired before the driver lock (the ifconfig case you spoke >> of, >> when the call is originating from a system call), but in the interrupt case, >> the driver lock would be acquired first, followed by Giant in the allocation >> routines. > > Sorry for disturbing this highly technical discussion, but all that > reminds me of some occasional kernel messages I've seen: > > Jan 19 07:53:05 myhakas /boot/smpkernel/kernel: lock order reversal > Jan 19 07:53:05 myhakas /boot/smpkernel/kernel: 1st fxp0 last acquired @ > ../../pci/if_fxp.c:842 > Jan 19 07:53:05 myhakas /boot/smpkernel/kernel: 2nd 0xc0f50520 fxp1 @ > ../../pci/if_fxp.c:993 > Jan 19 07:53:05 myhakas /boot/smpkernel/kernel: 3rd 0xc0f50920 fxp0 @ > ../../pci/if_fxp.c:842 > > I have two fxp and one ed (ne-2000 PCI clone) interfaces and bridge > defined. Those messages appear almost always in sync with traffic > over bridge interface(s). Is it something to care about? No, this is a bug in witness sort of. Or rather, I gave Bill Paul bad advice on naming device driver mutexes. Just ignore it for now. -- 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 cvs-all" in the body of the message
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