From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751958Ab1IZIqw (ORCPT ); Mon, 26 Sep 2011 04:46:52 -0400 Received: from casper.infradead.org ([85.118.1.10]:34887 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750764Ab1IZIqv convert rfc822-to-8bit (ORCPT ); Mon, 26 Sep 2011 04:46:51 -0400 Subject: Re: [PATCH 0/5] Reduce cross CPU IPI interference From: Peter Zijlstra To: Gilad Ben-Yossef Cc: linux-kernel@vger.kernel.org, Frederic Weisbecker , Russell King , Chris Metcalf , linux-mm@kvack.org, Christoph Lameter , Pekka Enberg , Matt Mackall Date: Mon, 26 Sep 2011 10:46:14 +0200 In-Reply-To: References: <1316940890-24138-1-git-send-email-gilad@benyossef.com> <1317021659.9084.51.camel@twins> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.0.3- Message-ID: <1317026774.9084.66.camel@twins> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-09-26 at 11:43 +0300, Gilad Ben-Yossef wrote: > On Mon, Sep 26, 2011 at 10:20 AM, Peter Zijlstra wrote: > > On Sun, 2011-09-25 at 11:54 +0300, Gilad Ben-Yossef wrote: > >> This first version creates an on_each_cpu_mask infrastructure API > > > > But we already have the existing smp_call_function_many() doing that. > > I might be wrong but my understanding is that smp_call_function_many() > does not invoke the IPI handler on the current processor. The original > code I replaced uses on_each_cpu() which does, so I figured a wrapper > was in order and then I discovered the same wrapper in arch specific > code. > > > The on_each_cpu() thing is mostly a hysterical relic and could be > > completely depricated > > Wont this require each caller to call smp_call_function_* and then > check to see if it needs to also invoke the IPI handler locally ? I > thought that was the reason for on_each_cpu existence... What have I > missed? Gah, you're right.. early.. tea.. more. Looks fine then. 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 ESMTP id B0F7D9000BD for ; Mon, 26 Sep 2011 04:46:47 -0400 (EDT) Subject: Re: [PATCH 0/5] Reduce cross CPU IPI interference From: Peter Zijlstra Date: Mon, 26 Sep 2011 10:46:14 +0200 In-Reply-To: References: <1316940890-24138-1-git-send-email-gilad@benyossef.com> <1317021659.9084.51.camel@twins> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Message-ID: <1317026774.9084.66.camel@twins> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Gilad Ben-Yossef Cc: linux-kernel@vger.kernel.org, Frederic Weisbecker , Russell King , Chris Metcalf , linux-mm@kvack.org, Christoph Lameter , Pekka Enberg , Matt Mackall On Mon, 2011-09-26 at 11:43 +0300, Gilad Ben-Yossef wrote: > On Mon, Sep 26, 2011 at 10:20 AM, Peter Zijlstra = wrote: > > On Sun, 2011-09-25 at 11:54 +0300, Gilad Ben-Yossef wrote: > >> This first version creates an on_each_cpu_mask infrastructure API > > > > But we already have the existing smp_call_function_many() doing that. >=20 > I might be wrong but my understanding is that smp_call_function_many() > does not invoke the IPI handler on the current processor. The original > code I replaced uses on_each_cpu() which does, so I figured a wrapper > was in order and then I discovered the same wrapper in arch specific > code. >=20 > > The on_each_cpu() thing is mostly a hysterical relic and could be > > completely depricated >=20 > Wont this require each caller to call smp_call_function_* and then > check to see if it needs to also invoke the IPI handler locally ? I > thought that was the reason for on_each_cpu existence... What have I > missed? Gah, you're right.. early.. tea.. more.=20 Looks fine then. -- 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