From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id B588A8D0040 for ; Sat, 26 Mar 2011 15:30:38 -0400 (EDT) Date: Sat, 26 Mar 2011 14:30:33 -0500 (CDT) From: Christoph Lameter Subject: Re: [PATCH] slub: Disable the lockless allocator In-Reply-To: Message-ID: References: <20110324142146.GA11682@elte.hu> <20110324172653.GA28507@elte.hu> <20110324185258.GA28370@elte.hu> <20110324192247.GA5477@elte.hu> <20110326112725.GA28612@elte.hu> <20110326114736.GA8251@elte.hu> <1301161507.2979.105.camel@edumazet-laptop> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Eric Dumazet Cc: Ingo Molnar , Pekka Enberg , Thomas Gleixner , torvalds@linux-foundation.org, akpm@linux-foundation.org, tj@kernel.org, npiggin@kernel.dk, rientjes@google.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Indeed I can reproduce it easily. With a few printk's this shows that alloc_percpu() returns a wrong address which is the cause of all of this: logs: Memory: 1011444k/1048564k available (11622k kernel code, 452k absent, 36668k reserved, 6270k data, 1028k init) alloc_kmem_cache_cpus kmem_cache_node = ffff88003ffcf000 alloc_kmem_cache_cpus kmem_cache = ffff88003ffcf020 This means that the cpu_slab is not a percpu pointer. Now the first allocation attempt: Slab kmem_cache cpu_slab=ffff88003ffcf020 freelist=ffff88003f8020c0 BUG: unable to handle kernel paging request at ffff87ffc1fdc020 IP: [] this_cpu_cmpxchg16b_emu+0x2/0x1c Tejun: Whats going on there? I should be getting offsets into the per cpu area and not kernel addresses. -- 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 internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org