From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with SMTP id B0BB66B0011 for ; Thu, 26 May 2011 14:17:24 -0400 (EDT) Date: Thu, 26 May 2011 13:17:11 -0500 (CDT) From: Christoph Lameter Subject: Re: [slubllv5 07/25] x86: Add support for cmpxchg_double In-Reply-To: <4DDE9670.3060709@zytor.com> Message-ID: References: <20110516202605.274023469@linux.com> <20110516202625.197639928@linux.com> <4DDE9670.3060709@zytor.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: "H. Peter Anvin" Cc: Pekka Enberg , David Rientjes , Eric Dumazet , linux-mm@kvack.org, Thomas Gleixner On Thu, 26 May 2011, H. Peter Anvin wrote: > > +config CMPXCHG_DOUBLE > > + def_bool X86_64 || (X86_32 && !M386) > > + > > CMPXCHG16B is not a baseline feature for the Linux x86-64 build, and > CMPXCHG8G is a Pentium, not a 486, feature. > > Nacked-by: H. Peter Anvin Hmmm... We may have to call it CONFIG_CMPXCHG_DOUBLE_POSSIBLE then? Because the slub code tests the flag in the processor and will not use the cmpxchg16b from the allocator if its not there. It will then fallback to using a bit lock in page struct. -- 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