From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail191.messagelabs.com (mail191.messagelabs.com [216.82.242.19]) by kanga.kvack.org (Postfix) with ESMTP id 74E8B8D0040 for ; Thu, 24 Mar 2011 14:22:10 -0400 (EDT) Received: by fxm18 with SMTP id 18so366489fxm.14 for ; Thu, 24 Mar 2011 11:22:08 -0700 (PDT) Subject: Re: [GIT PULL] SLAB changes for v2.6.39-rc1 From: Eric Dumazet In-Reply-To: References: <20110324142146.GA11682@elte.hu> <20110324172653.GA28507@elte.hu> Content-Type: text/plain; charset="UTF-8" Date: Thu, 24 Mar 2011 19:20:53 +0100 Message-ID: <1300990853.3747.189.camel@edumazet-laptop> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Pekka Enberg , Ingo Molnar , 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 Le jeudi 24 mars 2011 A 13:15 -0500, Christoph Lameter a A(C)crit : > But then we would get the bug in kmem_cache_alloc() and not in the > *_emu() function. So the _emu is executing but failing on Ingo's system > but not on mine. Question is why. > > For some reason the first reference to %gs:(%rsi) wont work right on his > system: > > From arch/x86/lib/cmpxchg16b_emu > > # > # Emulate 'cmpxchg16b %gs:(%rsi)' except we return the result in %al not > # via the ZF. Caller will access %al to get result. > # > # Note that this is only useful for a cpuops operation. Meaning that we > # do *not* have a fully atomic operation but just an operation that is > # *atomic* on a single cpu (as provided by the this_cpu_xx class of > # macros). > # > this_cpu_cmpxchg16b_emu: > pushf > cli > > cmpq %gs:(%rsi), %rax > jne not_same > cmpq %gs:8(%rsi), %rdx > jne not_same > > movq %rbx, %gs:(%rsi) > movq %rcx, %gs:8(%rsi) > > popf > mov $1, %al > ret > > not_same: > popf > xor %al,%al > ret > > CFI_ENDPROC Random guess Masking interrupts, and accessing vmalloc() based memory for the first time ? -- 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