Date: Mon, 29 Aug 2005 14:13:23 -0400 From: John Baldwin <jhb@FreeBSD.org> To: freebsd-current@freebsd.org Cc: bzeeb-lists@lists.zabbadoz.net, Robert Watson <rwatson@freebsd.org>, dandee@volny.cz, "M. Warner Losh" <imp@bsdimp.com> Subject: Re: LOR route vr0 Message-ID: <200508291413.25426.jhb@FreeBSD.org> In-Reply-To: <20050828051917.W52467@fledge.watson.org> References: <20050827184153.A24510@fledge.watson.org> <20050827.220303.130848154.imp@bsdimp.com> <20050828051917.W52467@fledge.watson.org>
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On Sunday 28 August 2005 12:20 am, Robert Watson wrote: > On Sat, 27 Aug 2005, M. Warner Losh wrote: > > : Correct. 'tcp' reflects the global TCP state tables (pcbinfo) locks, > > : and 'tcpinp' is for individual PCBs. If you acquire first a tcpinp and > > : then tcp, the above settings should cause WITNESS to generate a lock > > : order warning. Likewise, both tcp and tcpinp preceed so_snd, so if you > > : acquire a protocol lock after a socket lock, it will get unhappy. > > : WITNESS handles transitive relationships, so it gets connected up to > > : the rest of the lock graph, explicit and implicit, so indirect > > : violations of orders are fully handled. > > > > OK. I've been seeing similar LORs in ed, sn, iwi (ed is my locked > > version of ed, not in tree GIANT locked ed). > > > > I've made the following changes, and the LORs go away (except for one, > > which was unrelated). I further don't get the first place where they > > locks happen that caused the original LORs, so I'm mightly confused. > > Hmm. I've seen another identical report recently -- that when a lock > order is put into WITNESS, reversals against it are not reported. I > wonder if we've got a witness bug on our hands? Note that in this case the problem shows up because of a series of transitive lock orders. It would be useful to see the graph from show witness before you add the hard-coded entries to see why it thinks rtentry comes after MTX_NETWORK_LOCK. -- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org
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