From owner-svn-src-all@FreeBSD.ORG Tue Sep 2 17:24:00 2014 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 ESMTPS id 4A87CA76; Tue, 2 Sep 2014 17:24:00 +0000 (UTC) Received: from pp2.rice.edu (proofpoint2.mail.rice.edu [128.42.201.101]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 0CEB21985; Tue, 2 Sep 2014 17:23:59 +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 s82HCKU4008536; Tue, 2 Sep 2014 12:23:57 -0500 Received: from mh3.mail.rice.edu (mh3.mail.rice.edu [128.42.199.10]) by pp2.rice.edu with ESMTP id 1p574dgbh8-1; Tue, 02 Sep 2014 12:23:57 -0500 X-Virus-Scanned: by amavis-2.7.0 at mh3.mail.rice.edu, auth channel Received: from 108-254-203-201.lightspeed.hstntx.sbcglobal.net (108-254-203-201.lightspeed.hstntx.sbcglobal.net [108.254.203.201]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) (Authenticated sender: alc) by mh3.mail.rice.edu (Postfix) with ESMTPSA id 15013403F0; Tue, 2 Sep 2014 12:23:57 -0500 (CDT) Message-ID: <5405FD2C.8000901@rice.edu> Date: Tue, 02 Sep 2014 12:23:56 -0500 From: Alan Cox User-Agent: Mozilla/5.0 (X11; FreeBSD i386; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: John Baldwin , Peter Wemm Subject: Re: svn commit: r270759 - in head/sys: cddl/compat/opensolaris/kern cddl/compat/opensolaris/sys cddl/contrib/opensolaris/uts/common/fs/zfs vm References: <201408281950.s7SJo90I047213@svn.freebsd.org> <39211177.i8nn9sHiCx@overcee.wemm.org> <201409021201.15967.jhb@freebsd.org> In-Reply-To: <201409021201.15967.jhb@freebsd.org> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 kscore.is_bulkscore=0 kscore.compositescore=0 circleOfTrustscore=0 compositescore=0.248919945447816 urlsuspect_oldscore=0.248919945447816 suspectscore=11 recipient_domain_to_sender_totalscore=0 phishscore=0 bulkscore=0 kscore.is_spamscore=0 recipient_to_sender_totalscore=0 recipient_domain_to_sender_domain_totalscore=0 rbsscore=0.248919945447816 spamscore=0 recipient_to_sender_domain_totalscore=0 urlsuspectscore=0.9 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000 definitions=main-1409020196 Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, Dmitry Morozovsky , "Matthew D. Fuller" , svn-src-head@freebsd.org, Steven Hartland X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.18-1 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: Tue, 02 Sep 2014 17:24:00 -0000 On 09/02/2014 11:01, John Baldwin wrote: > On Saturday, August 30, 2014 1:37:43 pm Peter Wemm wrote: >> On Saturday 30 August 2014 02:03:42 Steven Hartland wrote: >> I'm very disappointed in the attention to detail and errors in the commit. >> I'm almost at the point where I want to ask for the whole thing to be backed >> out. > I would not be too supportive of that. This PR has been open for a long, long > time with many users using patches from it in production loads that were > greatly improved by the changes and clamoring on the lists multiple times to > get someone to look at it. avg@ contributed quite a bit of time to diagnose > this with Karl early on, but other developers aside from Steven did not. It > also was not hard to explain to Karl the meaning of 'cache + free' in the bug > follow-ups itself (though I believe avg@ had tried this before and it didn't > sink in that time for some reason). > > I know Steven has since committed a fix, but if there are still concerns, I > think it would be best to not just revert this entirely but to spend some time > fixing the remaining issues. Clearly this issue affects a lot of users and > the earlier fixes to pagedaemon were not sufficient to fix their issues alone. > The patch actually makes two completely orthogonal changes at once, and one of those changes has no connection to the page daemon. I suspect that is why some people have said that their issues were not addressed by the page daemon fix. Prior to this patch, we were limiting the ARC size to 3/4 the kmem map/arena/object size on all architectures, including 64-bit, uma_small_alloc-enabled architectures where such a limit makes no sense. Consequently, some people were complaining, "Why is 1/4 of my memory going unused?"