From owner-freebsd-stable Tue May 25 8: 4: 9 1999 Delivered-To: freebsd-stable@freebsd.org Received: from point.osg.gov.bc.ca (point.osg.gov.bc.ca [142.32.102.44]) by hub.freebsd.org (Postfix) with ESMTP id 7799315782; Tue, 25 May 1999 08:04:05 -0700 (PDT) (envelope-from Cy.Schubert@uumail.gov.bc.ca) Received: (from daemon@localhost) by point.osg.gov.bc.ca (8.8.7/8.8.8) id IAA04316; Tue, 25 May 1999 08:06:32 -0700 Received: from passer.osg.gov.bc.ca(142.32.110.29) via SMTP by point.osg.gov.bc.ca, id smtpda04314; Tue May 25 08:06:16 1999 Received: (from uucp@localhost) by passer.osg.gov.bc.ca (8.9.3/8.9.1) id IAA33951; Tue, 25 May 1999 08:03:38 -0700 (PDT) Message-Id: <199905251503.IAA33951@passer.osg.gov.bc.ca> Received: from localhost.osg.gov.bc.ca(127.0.0.1), claiming to be "passer.osg.gov.bc.ca" via SMTP by localhost.osg.gov.bc.ca, id smtpdz33940; Tue May 25 08:03:08 1999 X-Mailer: exmh version 2.0.2 2/24/98 Reply-To: Cy Schubert - ITSD Open Systems Group X-OS: FreeBSD 3.1-RELEASE X-Sender: cschuber To: Matthew Dillon Cc: Cy Schubert - ITSD Open Systems Group , dg@root.com, Cliff Skolnick , Mike Tancsa , freebsd-stable@FreeBSD.ORG, luoqi@FreeBSD.ORG Subject: Re: vm_fault deadlock and PR 8416 ... NOT fixed! In-reply-to: Your message of "Fri, 21 May 1999 20:04:47 PDT." <199905220304.UAA69597@apollo.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 25 May 1999 08:03:08 -0700 From: Cy Schubert Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <199905220304.UAA69597@apollo.backplane.com>, Matthew Dillon writes: > :Would plan B risk corruption of any data? Could itself be the likely > :cause of any potential panics? > : > :Assuming plan B has no major risks, this might be a temporary > :workaround until we can wrap our minds around this one. It's just a > :rework of Luoqi's patch, just in case we want to try plan B again. > : > :--- kern_lock.c.orig Tue May 11 08:34:52 1999 > :+++ kern_lock.c Wed May 12 05:38:52 1999 > :@@ -215,7 +215,9 @@ > : * lock itself ). > : */ > : if (lkp->lk_lockholder != pid) { > :- if (p->p_flag & P_DEADLKTREAT) { > :+ if ((p->p_flag & P_DEADLKTREAT) || > :+ ((lkp->lk_flags & LK_SHARE_NONZERO) != 0 && > :+ (flags & LK_CANRECURSE) != 0) { > : error = acquire( > : lkp, > : extflags, > : > :If this workaround doesn't work, then setting error = 0 and allowing > :the code to fall through to the subsequent sharelock may be our only > :choice for now. > : > :The other point I wish to make for all on this list is that Matt's > :patch fixes a read()/mmap() deadlock. It doesn't fix a write()/mmap() > :deadlock. > : > : > :Regards, Phone: (250)387-8437 > :Cy Schubert Fax: (250)387-5766 > > It's an interesting workaround, but a bit too complex. That is, the > locking is becoming a too complex. We are going to screw ourselves if > we keep patching it. ... I came to the same conclusion last week. Regards, Phone: (250)387-8437 Cy Schubert Fax: (250)387-5766 Open Systems Group Internet: Cy.Schubert@uumail.gov.bc.ca ITSD Cy.Schubert@gems8.gov.bc.ca Province of BC "e**(i*pi)+1=0" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message