Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757284AbZJBJTB (ORCPT ); Fri, 2 Oct 2009 05:19:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754881AbZJBJTA (ORCPT ); Fri, 2 Oct 2009 05:19:00 -0400 Received: from hera.kernel.org ([140.211.167.34]:56668 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753493AbZJBJS7 (ORCPT ); Fri, 2 Oct 2009 05:18:59 -0400 Message-ID: <4AC5C572.9040309@kernel.org> Date: Fri, 02 Oct 2009 18:18:42 +0900 From: Tejun Heo User-Agent: Thunderbird 2.0.0.22 (X11/20090605) MIME-Version: 1.0 To: cl@linux-foundation.org CC: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, mingo@elte.hu, rusty@rustcorp.com.au, Pekka Enberg Subject: Re: [this_cpu_xx V4 02/20] this_cpu: X86 optimized this_cpu operations References: <20091001212521.123389189@gentwo.org> <20091001212557.963565363@gentwo.org> In-Reply-To: <20091001212557.963565363@gentwo.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 02 Oct 2009 09:18:44 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 936 Lines: 23 cl@linux-foundation.org wrote: > Basically the existing percpu ops can be used for this_cpu variants that allow > operations also on dynamically allocated percpu data. However, we do not pass a > reference to a percpu variable in. Instead a dynamically or statically > allocated percpu variable is provided. > > Preempt, the non preempt and the irqsafe operations generate the same code. > It will always be possible to have the requires per cpu atomicness in a single > RMW instruction with segment override on x86. > > 64 bit this_cpu operations are not supported on 32 bit. > > Signed-off-by: Christoph Lameter Acked-by: Tejun Heo -- tejun -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/