From owner-freebsd-stable@FreeBSD.ORG Thu Nov 14 11:26:38 2013 Return-Path: Delivered-To: freebsd-stable@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 8A50D3B7 for ; Thu, 14 Nov 2013 11:26:38 +0000 (UTC) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id DC8CE21DD for ; Thu, 14 Nov 2013 11:26:37 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id NAA07605; Thu, 14 Nov 2013 13:26:18 +0200 (EET) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1Vgv3y-000O94-E7; Thu, 14 Nov 2013 13:26:18 +0200 Message-ID: <5284B322.1070806@FreeBSD.org> Date: Thu, 14 Nov 2013 13:25:22 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 MIME-Version: 1.0 To: hartzell@alerce.com Subject: Re: Help with filing a [maybe] ZFS/mmap bug. References: <20967.760.95825.310085@gargle.gargle.HOWL> <51E80B30.1090004@FreeBSD.org> <20968.10645.880772.30501@gargle.gargle.HOWL> <520202E5.30300@FreeBSD.org> <21055.33473.385334.574140@gargle.gargle.HOWL> In-Reply-To: <21055.33473.385334.574140@gargle.gargle.HOWL> X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: freebsd-stable@FreeBSD.org X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 Nov 2013 11:26:38 -0000 on 23/09/2013 02:52 George Hartzell said the following: > This weekend I built up a system using the 10.0 beta 2 dvd, then > updated /usr/src from head. > > I grabbed a fresh copy of your patch this afternoon. > > I applied your patch with no problems. I was unable to build a new > kernel though, you have one reference to m->busy, where m is a > vm_page_t (if I remember correctly). I dug around a bit and decided > that you meant m->busy_lock, which let me build a usable kernel. > > It looks like INVARIANTS and INVARIANT_SUPPORT are included in the > GENERIC conf file. > > I ran through my test routine with the original system and was able to > reproduce the problem. > > After building and installing a kernel with your patch I was still > able to trigger the problem. If anything it was worse (sample size = > 1, I know...). > > I did not see any interesting output in /var/log/messages or to the > console or anywhere else obvious. > > I'm not sure what to do next. It's likely that my m->busy to > m->busy_lock change was not The Right Thing to Do and might have > invalidated what the patch was trying to do. > > In any case, I now have a system running HEAD and should be able to > test things more easily. George, thank you very much for the test! And sorry for the "delay" with my reply. I was out of new ideas at first and then very busy. But now Steve has woken me up :-) The busy -> busy_lock change was not entirely correct, but it is pretty harmless. I will probably commit the putpages patch anyway soon. But your test confirms that the pageout logic was not related to the bug. I think I now have an idea of what could be wrong. I will follow up in the other thread. -- Andriy Gapon