From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from d01relay02.pok.ibm.com (d01relay02.pok.ibm.com [9.56.227.234]) by e1.ny.us.ibm.com (8.13.1/8.13.1) with ESMTP id mB5HH8Xk030676 for ; Fri, 5 Dec 2008 12:17:08 -0500 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id mB5HHfiK178972 for ; Fri, 5 Dec 2008 12:17:41 -0500 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id mB5IHoWF026575 for ; Fri, 5 Dec 2008 13:17:51 -0500 Subject: Re: [Bug 12134] New: can't shmat() 1GB hugepage segment from second process more than one time From: Adam Litke In-Reply-To: <6.2.5.6.2.20081203221021.01cf8e88@binnacle.cx> References: <20081201181459.49d8fcca.akpm@linux-foundation.org> <1228245880.13482.19.camel@localhost.localdomain> <6.2.5.6.2.20081203221021.01cf8e88@binnacle.cx> Content-Type: text/plain Date: Fri, 05 Dec 2008 11:17:30 -0600 Message-Id: <1228497450.13428.26.camel@localhost.localdomain> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: starlight@binnacle.cx Cc: Andrew Morton , linux-mm@kvack.org, bugme-daemon@bugzilla.kernel.org, Andy Whitcroft , David Gibson List-ID: On Wed, 2008-12-03 at 22:15 -0500, starlight@binnacle.cx wrote: > At 13:24 12/2/2008 -0600, Adam Litke wrote: > >starlight@binnacle.cx: I need more information > >to reproduce this bug. > > I'm too swamped to build a test-case, but here are straces > that show the relevant system calls and the failure. Starlight, Thanks for the strace output. As I suspected, this is more complex than it first appeared. There are several hugetlb shared memory segments involved. Couple that with threading and an interesting approach to mlocking the address space and I've got a very difficult to reproduce scenario. Is it possible/practical for me to have access to your program? If so, I could quickly bisect the kernel and identify the guilty patch. Without the program, I am left stabbing in the dark. Could you try on a 2.6.18 kernel to see if it works or not? Thanks. -- Adam Litke - (agl at us.ibm.com) IBM Linux Technology Center -- 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