From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 160F56B002D for ; Sat, 29 Oct 2011 11:29:44 -0400 (EDT) Received: by ywa17 with SMTP id 17so5986594ywa.14 for ; Sat, 29 Oct 2011 08:29:41 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <4EAAD351.70805@redhat.com> References: <1319385413-29665-1-git-send-email-gilad@benyossef.com> <1319385413-29665-5-git-send-email-gilad@benyossef.com> <4EAAD351.70805@redhat.com> Date: Sat, 29 Oct 2011 17:29:41 +0200 Message-ID: Subject: Re: [PATCH v2 4/6] mm: Only IPI CPUs to drain local pages if they exist From: Gilad Ben-Yossef Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Rik van Riel Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Frederic Weisbecker , Russell King , linux-mm@kvack.org, Christoph Lameter , Pekka Enberg , Matt Mackall , Sasha Levin On Fri, Oct 28, 2011 at 6:07 PM, Rik van Riel wrote: > On 10/23/2011 11:56 AM, Gilad Ben-Yossef wrote: >> >> Use a cpumask to track CPUs with per-cpu pages in any zone >> and only send an IPI requesting CPUs to drain these pages >> to the buddy allocator if they actually have pages. > >> +/* Which CPUs have per cpu pages =A0*/ >> +cpumask_var_t cpus_with_pcp; >> +static DEFINE_PER_CPU(unsigned long, total_cpu_pcp_count); > > Does the flushing happen so frequently that it is worth keeping this > state on a per-cpu basis, or would it be better to check each CPU's > pcp info and assemble a cpumask at flush time like done in patch 5? > No, I don't believe it is frequent at all. I will try to re-work the patch as suggested. Thanks, Gilad > > > -- > All rights reversed > --=20 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