Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757501AbZJBJ72 (ORCPT ); Fri, 2 Oct 2009 05:59:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757461AbZJBJ71 (ORCPT ); Fri, 2 Oct 2009 05:59:27 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:35921 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756728AbZJBJ70 (ORCPT ); Fri, 2 Oct 2009 05:59:26 -0400 Date: Fri, 2 Oct 2009 11:59:16 +0200 From: Ingo Molnar To: cl@linux-foundation.org Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, Tejun Heo , rusty@rustcorp.com.au, Pekka Enberg Subject: Re: [this_cpu_xx V4 02/20] this_cpu: X86 optimized this_cpu operations Message-ID: <20091002095916.GA26201@elte.hu> References: <20091001212521.123389189@gentwo.org> <20091001212557.963565363@gentwo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091001212557.963565363@gentwo.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 969 Lines: 24 * 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: Ingo Molnar Ingo -- 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/