From owner-freebsd-stable@FreeBSD.ORG Mon Oct 26 13:10:33 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C57D51065695 for ; Mon, 26 Oct 2009 13:10:33 +0000 (UTC) (envelope-from arnaud.houdelette@tzim.net) Received: from golanth.tzim.net (unknown [IPv6:2001:41d0:1:d91f:21c:c0ff:fe4b:cf32]) by mx1.freebsd.org (Postfix) with ESMTP id 623B98FC1B for ; Mon, 26 Oct 2009 13:10:33 +0000 (UTC) Received: from alarante.irisa.fr ([131.254.13.244]) by golanth.tzim.net with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1N2PLA-0004vP-Bu; Mon, 26 Oct 2009 14:10:28 +0100 Message-ID: <4AE59FBE.6060904@tzim.net> Date: Mon, 26 Oct 2009 14:10:22 +0100 From: Arnaud Houdelette User-Agent: Thunderbird 2.0.0.21 (Macintosh/20090302) MIME-Version: 1.0 To: Jaime Bozza References: <4AE2232E.10406@whotookspaz.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Authenticated-User: tzim@tzim.net X-Authenticator: plain Cc: "freebsd-stable@freebsd.org" , Jacob Myers Subject: Re: Possible scheduler (SCHED_ULE) bug? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Oct 2009 13:10:33 -0000 Jaime Bozza a écrit : >>> The additional information I have (over the PR) is that: >>> 1) Files over 64K cause the problem, not just larger files >>> >> I thought it was over 1 MB or so. But maybe I'm wrong. ISTR that I >> couldn't trigger it with some images of around 70K. >> > > I discovered it originally with a 72K file. After some tests, I found a 63K file worked and a 65K file didn't. When I get back into the office, I can test the actual boundary (65535, 65536, 65537, etc), but 64K seems pretty logical. > > >>> 2) switching over to SCHED_4BSD eliminates the problem - system no >>> >> longer locks. >> I will have to test this. This is indeed interesting... >> >> >>> 3) 7.2 amd64 doesn't have the problem - Tested a similar >>> >> configuration and was not able to duplicate on amd64 at all. >> I can replicate this problem on FreeBSD 7.2/amd64 reliably. >> > > I haven't tried larger files - Maybe the boundary is different on amd64? Doing some quick tests right now, I was able to upload a 100MB file without a problem, but this is an AMD64 system with SMP, plus the filesystem is all ZFS, so there are too many things different. I'll have to setup a system that closely mirrors the rest of my tests (UFS, ULE, no SMP, etc) before I can say I'm not having a problem there. > > Jaime > I had the same issue using 7.1 amd64, with ZFS, no SMP. Not really sure what is the size boundary. I can't really test either, as the machine is remote. But I confirm that each tentative upload of certain relatively 'big' files (around 1MB) with wordpress hanged the system before I switched from sendfile to writev. I might do some test on amd64 7.2 with no SMP if it can be of any use ? Arnaud