From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 5C8518D0002 for ; Wed, 1 Dec 2010 16:40:53 -0500 (EST) Received: from kpbe20.cbf.corp.google.com (kpbe20.cbf.corp.google.com [172.25.105.84]) by smtp-out.google.com with ESMTP id oB1LemCb022689 for ; Wed, 1 Dec 2010 13:40:49 -0800 Received: from vws6 (vws6.prod.google.com [10.241.21.134]) by kpbe20.cbf.corp.google.com with ESMTP id oB1LeFer032582 for ; Wed, 1 Dec 2010 13:40:47 -0800 Received: by vws6 with SMTP id 6so2888630vws.6 for ; Wed, 01 Dec 2010 13:40:43 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <919384632.877731291171499343.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> <1330724443.975931291231775834.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> Date: Wed, 1 Dec 2010 13:40:43 -0800 Message-ID: Subject: Re: oom is broken in mmotm 2010-11-09-15-31 tree? From: Michel Lespinasse Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org To: Linus Torvalds Cc: CAI Qian , linux-mm , Rik van Riel , Wu Fengguang , "H. Peter Anvin" List-ID: On Wed, Dec 1, 2010 at 12:15 PM, Linus Torvalds wrote: > On Wed, Dec 1, 2010 at 11:29 AM, CAI Qian wrote: >>> >>> Hi, just a head-up. When testing oom for this tree, my workstation is >>> immediately having no response to ssh, Desktop actions and so on apart >>> from ping. I am trying to bisect but looks like git public server is >>> having problem. >> >> This turned out that it was introduced by, >> >> =A0d065bd810b6deb67d4897a14bfe21f8eb526ba99 >> =A0mm: retry page fault when blocking on disk transfer >> >> It was reproduced by: >> 1) ssh to the test box. >> 2) try to trigger oom a few times using a malloc program there. > > Interesting. That commit is not supposed to make any semantic > difference at all. And even if we do end up in the retry path, the > arch/x86/mm/fault.c code is very explicitly designed so that it > retries only _once_. > > Michel, any ideas? I could see problems with the mmap_sem if > VM_FAULT_OOM is set at the same time as VM_FAULT_RETRY, but I can't > see how that could ever happen. > > Anybody? > > CAI, can you get any output from sysrq-W when this happens? Things are known to be broken between d065bd810b6deb67d4897a14bfe21f8eb526ba99 and d88c0922fa0e2c021a028b310a641126c6d4b7dc. CAI, do you have that in your tree ? Also, can you test at d065bd810b6deb67d4897a14bfe21f8eb526ba99 with d88c0922fa0e2c021a028b310a641126c6d4b7dc cherry-picked on ? --=20 Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org