From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail172.messagelabs.com (mail172.messagelabs.com [216.82.254.3]) by kanga.kvack.org (Postfix) with ESMTP id 37C2D9000BD for ; Mon, 26 Sep 2011 04:43:56 -0400 (EDT) Received: by ywe9 with SMTP id 9so5529695ywe.14 for ; Mon, 26 Sep 2011 01:43:54 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1317021659.9084.51.camel@twins> References: <1316940890-24138-1-git-send-email-gilad@benyossef.com> <1317021659.9084.51.camel@twins> Date: Mon, 26 Sep 2011 11:43:54 +0300 Message-ID: Subject: Re: [PATCH 0/5] Reduce cross CPU IPI interference From: Gilad Ben-Yossef Content-Type: text/plain; charset=ISO-8859-1 Sender: owner-linux-mm@kvack.org List-ID: To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Frederic Weisbecker , Russell King , Chris Metcalf , linux-mm@kvack.org, Christoph Lameter , Pekka Enberg , Matt Mackall 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? Thanks, Gilad -- Gilad Ben-Yossef Chief Coffee Drinker gilad@benyossef.com Israel Cell: +972-52-8260388 US Cell: +1-973-8260388 http://benyossef.com "I've seen things you people wouldn't believe. Goto statements used to implement co-routines. I watched C structures being stored in registers. All those moments will be lost in time... like tears in rain... Time to die. " -- 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