From owner-svn-src-all@FreeBSD.ORG Fri Aug 9 20:42:02 2013 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTP id 59BC23CC; Fri, 9 Aug 2013 20:42:02 +0000 (UTC) (envelope-from alc@rice.edu) Received: from pp2.rice.edu (proofpoint2.mail.rice.edu [128.42.201.101]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 23793215E; Fri, 9 Aug 2013 20:42:01 +0000 (UTC) Received: from pps.filterd (pp2.rice.edu [127.0.0.1]) by pp2.rice.edu (8.14.5/8.14.5) with SMTP id r79Cdj8J014083; Fri, 9 Aug 2013 15:42:01 -0500 Received: from mh2.mail.rice.edu (mh2.mail.rice.edu [128.42.201.21]) by pp2.rice.edu with ESMTP id 1e41r810n7-1; Fri, 09 Aug 2013 15:42:01 -0500 X-Virus-Scanned: by amavis-2.7.0 at mh2.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 mh2.mail.rice.edu (Postfix) with ESMTPSA id 9E9E0500110; Fri, 9 Aug 2013 15:42:00 -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: <201308091639.30727.jhb@freebsd.org> Date: Fri, 9 Aug 2013 13:41:56 -0700 Content-Transfer-Encoding: quoted-printable Message-Id: References: <201308091643.r79GhoWx023884@svn.freebsd.org> <201308091556.47535.jhb@freebsd.org> <201308091639.30727.jhb@freebsd.org> To: John Baldwin 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" 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 20:42:02 -0000 On Aug 9, 2013, at 1:39 PM, John Baldwin wrote: > On Friday, August 09, 2013 4:34:36 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=20 > 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 > That is going to recurse on vm_page_lock(), is that ok? >=20 No, it's not. >>> + 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 >=20 > --=20 > John Baldwin >=20