From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 12 Jun 2008 12:20:09 -0700 From: Andrew Morton Subject: Re: repeatable slab corruption with LTP msgctl08 Message-Id: <20080612122009.f4d3a82a.akpm@linux-foundation.org> In-Reply-To: <48517456.5000901@colorfullife.com> References: <20080611221324.42270ef2.akpm@linux-foundation.org> <48516BF3.8050805@colorfullife.com> <20080612114152.18895d6c.akpm@linux-foundation.org> <48517456.5000901@colorfullife.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Manfred Spraul Cc: penberg@cs.helsinki.fi, Nadia.Derbey@bull.net, linux-kernel@vger.kernel.org, linux-mm@kvack.org, clameter@sgi.com List-ID: On Thu, 12 Jun 2008 21:09:10 +0200 Manfred Spraul wrote: > Either someone does a set_bit() or your cpu is breaking down. Well. It is about ten years old. But this is the first sign of a problem and it's always msgctl08. > From looking at the the msgctl08 test: it shouldn't produce any races, > it just does lots of bulk msgsnd()/msgrcv() operations. Always one > thread sends, one thread receives on each queue. It's probably more a > scheduler stresstest than anything else. > > Attached is a completely untested patch: > - add 8 bytes to each slabp struct: This changes the alignment of the > bufctl entries. > - add a hexdump of the redzone bytes. OK, I'll try that this evening (eight hours hence). I'll also try increasing /proc/sys/kernel/msgmni under 2.6.25. > Andrew: how do you log the oops? > it might scroll of the screen. netconsole-to-disk. -- 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