From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f182.google.com (mail-pd0-f182.google.com [209.85.192.182]) by kanga.kvack.org (Postfix) with ESMTP id E3EBD6B003A for ; Tue, 29 Apr 2014 04:03:02 -0400 (EDT) Received: by mail-pd0-f182.google.com with SMTP id v10so2403398pde.13 for ; Tue, 29 Apr 2014 01:03:02 -0700 (PDT) Received: from e28smtp04.in.ibm.com (e28smtp04.in.ibm.com. [122.248.162.4]) by mx.google.com with ESMTPS id ps1si12128829pbc.293.2014.04.29.01.03.00 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 29 Apr 2014 01:03:02 -0700 (PDT) Received: from /spool/local by e28smtp04.in.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 29 Apr 2014 13:32:55 +0530 Received: from d28relay03.in.ibm.com (d28relay03.in.ibm.com [9.184.220.60]) by d28dlp02.in.ibm.com (Postfix) with ESMTP id 2F3903940048 for ; Tue, 29 Apr 2014 13:32:52 +0530 (IST) Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay03.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id s3T82k3H2752918 for ; Tue, 29 Apr 2014 13:32:46 +0530 Received: from d28av04.in.ibm.com (localhost [127.0.0.1]) by d28av04.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id s3T82p8N009875 for ; Tue, 29 Apr 2014 13:32:51 +0530 Message-ID: <535F5C7F.3000608@linux.vnet.ibm.com> Date: Tue, 29 Apr 2014 13:32:07 +0530 From: "Srivatsa S. Bhat" MIME-Version: 1.0 Subject: Re: [BUG] kernel BUG at mm/vmacache.c:85! References: <535EA976.1080402@linux.vnet.ibm.com> <1398724754.25549.35.camel@buesod1.americas.hpqcorp.net> In-Reply-To: <1398724754.25549.35.camel@buesod1.americas.hpqcorp.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Davidlohr Bueso Cc: Linus Torvalds , Linux MM , "linux-kernel@vger.kernel.org" , Rik van Riel , Michel Lespinasse , Hugh Dickins , "akpm@linux-foundation.org" , Oleg Nesterov On 04/29/2014 04:09 AM, Davidlohr Bueso wrote: > Adding Oleg. > > On Mon, 2014-04-28 at 14:55 -0700, Linus Torvalds wrote: >> On Mon, Apr 28, 2014 at 2:20 PM, Linus Torvalds >> wrote: >>> >>> That said, the bug does seem to be that some path doesn't invalidate >>> the vmacache sufficiently, or something inserts a vmacache entry into >>> the current process when looking up a remote process or whatever. >>> Davidlohr, ideas? >> >> Maybe we missed some use_mm() call. That will change the current mm >> without flushing the vma cache. The code considers kernel threads to >> be bad targets for vma caching for this reason (and perhaps others), >> but maybe we missed something. >> >> I wonder if we should just invalidate the vma cache in use_mm(), and >> remote the "kernel tasks are special" check. >> >> Srivatsa, are you doing something peculiar on that system that would >> trigger this? I see some kdump failures in the log, anything else? > > Is this perhaps a KVM guest? fwiw I see CONFIG_KVM_ASYNC_PF=y which is a > user of use_mm(). > No, this is just running baremetal on x86. I copied the kernel config of a distro kernel and reused it. Regards, Srivatsa S. Bhat -- 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/ . Don't email: email@kvack.org