From owner-svn-src-all@FreeBSD.ORG Fri Aug 9 20:40:16 2013 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id DA98927B; Fri, 9 Aug 2013 20:40:16 +0000 (UTC) (envelope-from alc@rice.edu) Received: from pp1.rice.edu (proofpoint1.mail.rice.edu [128.42.201.100]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id A63352127; Fri, 9 Aug 2013 20:40:16 +0000 (UTC) Received: from pps.filterd (pp1.rice.edu [127.0.0.1]) by pp1.rice.edu (8.14.5/8.14.5) with SMTP id r796viBW023230; Fri, 9 Aug 2013 15:40:15 -0500 Received: from mh10.mail.rice.edu (mh10.mail.rice.edu [128.42.201.30]) by pp1.rice.edu with ESMTP id 1dsymjr13a-1; Fri, 09 Aug 2013 15:40:15 -0500 X-Virus-Scanned: by amavis-2.7.0 at mh10.mail.rice.edu, auth channel Received: from [10.104.199.154] (unknown [131.107.165.33]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) (Authenticated sender: alc) by mh10.mail.rice.edu (Postfix) with ESMTPSA id DF9C4603E0; Fri, 9 Aug 2013 15:40:14 -0500 (CDT) Subject: Re: svn commit: r254150 - head/sys/vm Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: text/plain; charset=us-ascii From: Alan Cox In-Reply-To: Date: Fri, 9 Aug 2013 13:40:10 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: <655524DF-4DE9-428C-8A6A-C1A395489EF5@rice.edu> References: <201308091643.r79GhoWx023884@svn.freebsd.org> <201308091556.47535.jhb@freebsd.org> To: Alan Cox X-Mailer: Apple Mail (2.1085) Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, "David E. O'Brien" , John Baldwin X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Aug 2013 20:40:16 -0000 On Aug 9, 2013, at 1:34 PM, Alan Cox wrote: >=20 > On Aug 9, 2013, at 12:56 PM, John Baldwin wrote: >=20 >> On Friday, August 09, 2013 12:43:50 pm David E. O'Brien wrote: >>> Author: obrien >>> Date: Fri Aug 9 16:43:50 2013 >>> New Revision: 254150 >>> URL: http://svnweb.freebsd.org/changeset/base/254150 >>>=20 >>> Log: >>> Add missing 'VPO_BUSY' from r254141 to fix kernel build break. >>>=20 >>> Modified: >>> head/sys/vm/vm_page.h >>=20 >> This can't possibly be correct as r254138 just removed this flag. If = it isn't=20 >> obvious how to fix the uses added back in r254141, then r254141 = should be=20 >> reverted instead. >>=20 >> Hmm, looking at the relevant bits of r254141, it doesn't look = obvious: >>=20 >> + /* Detach the old page from the resident tailq. */ >> + TAILQ_REMOVE(&object->memq, mold, listq); >> + vm_page_lock(mold); >=20 > Replace the next four lines with >=20 > vm_page_xunbusy(mold); >=20 On second thought, no, because it could lead to lock recursion. >> + if (mold->oflags & VPO_BUSY) { >> + mold->oflags &=3D ~VPO_BUSY; >> + vm_page_flash(mold); >> + } >>=20 >> Since nothing is setting this flag, this can't possibly work = correctly=20 >> currently. I wouldn't boot a top-of-tree kernel right now. :( >>=20 >> --=20 >> John Baldwin >>=20 >=20 >=20