From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id C2ACB6B0011 for ; Tue, 31 May 2011 11:23:23 -0400 (EDT) Message-ID: <4DE50632.90906@zytor.com> Date: Tue, 31 May 2011 08:16:02 -0700 From: "H. Peter Anvin" MIME-Version: 1.0 Subject: Re: [slubllv5 07/25] x86: Add support for cmpxchg_double References: <20110516202605.274023469@linux.com> <20110516202625.197639928@linux.com> <4DDE9670.3060709@zytor.com> <4DDE9C01.2090104@zytor.com> <1306445159.2543.25.camel@edumazet-laptop> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Lameter Cc: Eric Dumazet , Pekka Enberg , David Rientjes , linux-mm@kvack.org, Thomas Gleixner On 05/31/2011 08:13 AM, Christoph Lameter wrote: > On Thu, 26 May 2011, Eric Dumazet wrote: > >>> +#define cmpxchg16b(ptr, o1, o2, n1, n2) \ >>> +({ \ >>> + char __ret; \ >>> + __typeof__(o2) __junk; \ >>> + __typeof__(*(ptr)) __old1 = (o1); \ >>> + __typeof__(o2) __old2 = (o2); \ >>> + __typeof__(*(ptr)) __new1 = (n1); \ >>> + __typeof__(o2) __new2 = (n2); \ >>> + asm volatile(LOCK_PREFIX_HERE "lock; cmpxchg16b (%%rsi);setz %1" \ >> >> If there is no emulation, why do you force rsi here ? >> >> It could be something else, like "=m" (*ptr) ? >> >> (same remark for other functions) > > Well I ran into trouble with =m. Maybe +m will do. Will try again. > Yes, =m would be very wrong indeed. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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