From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id C85436B00BA for ; Wed, 23 Nov 2011 02:13:54 -0500 (EST) Date: Wed, 23 Nov 2011 08:13:49 +0100 From: Markus Trippelsdorf Subject: Re: WARNING: at mm/slub.c:3357, kernel BUG at mm/slub.c:3413 Message-ID: <20111123071349.GA1671@x4.trippels.de> References: <1321895706.10470.21.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <20111121173556.GA1673@x4.trippels.de> <1321900743.10470.31.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> <20111121185215.GA1673@x4.trippels.de> <20111121195113.GA1678@x4.trippels.de> <1321907275.13860.12.camel@pasglop> <1321948113.27077.24.camel@edumazet-laptop> <1321950432.27077.27.camel@edumazet-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1321950432.27077.27.camel@edumazet-laptop> Sender: owner-linux-mm@kvack.org List-ID: To: Eric Dumazet Cc: Christoph Lameter , Christian Kujau , Benjamin Herrenschmidt , "Alex,Shi" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Pekka Enberg , Matt Mackall , "netdev@vger.kernel.org" , Tejun Heo On 2011.11.22 at 09:27 +0100, Eric Dumazet wrote: > Le mardi 22 novembre 2011 a 08:48 +0100, Eric Dumazet a ecrit : > > > For x86, I wonder if our !X86_FEATURE_CX16 support is correct on SMP > > machines. > > > > > By the way, I wonder why we still emit this_cpu_cmpxchg16b_emu() code > and calls when compiling a kernel for a cpu implementing cmpxchg16b > > (CONFIG_MCORE2=y) Yeah, it's strange (CONFIG_MK8): ffffffff811058b0 <__kmalloc>: ... ffffffff8110594f: 48 8d 4a 04 lea 0x4(%rdx),%rcx ffffffff81105953: 49 8b 1c 04 mov (%r12,%rax,1),%rbx ffffffff81105957: 4c 89 e0 mov %r12,%rax ffffffff8110595a: e8 11 70 10 00 callq ffffffff8120c970 ffffffff8110595f: 66 66 90 data32 xchg %ax,%ax ffffffff81105962: 84 c0 test %al,%al ffffffff81105964: 74 c6 je ffffffff8110592c <__kmalloc+0x7c> ... There is a comment in arch/x86/include/asm/percpu.h: * Pretty complex macro to generate cmpxchg16 instruction. The instruction * is not supported on early AMD64 processors so we must be able to emulate * it in software. The address used in the cmpxchg16 instruction must be * aligned to a 16 byte boundary. -- Markus -- 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