Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761924AbZLKAOQ (ORCPT ); Thu, 10 Dec 2009 19:14:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761891AbZLKAOO (ORCPT ); Thu, 10 Dec 2009 19:14:14 -0500 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:47442 "EHLO fgwmail7.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761886AbZLKAOO (ORCPT ); Thu, 10 Dec 2009 19:14:14 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 Date: Fri, 11 Dec 2009 09:11:14 +0900 From: KAMEZAWA Hiroyuki To: Ingo Molnar Cc: Christoph Lameter , Peter Zijlstra , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , minchan.kim@gmail.com Subject: Re: [RFC mm][PATCH 2/5] percpu cached mm counter Message-Id: <20091211091114.c5fa4371.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20091210185459.GA8697@elte.hu> References: <20091210163115.463d96a3.kamezawa.hiroyu@jp.fujitsu.com> <20091210163448.338a0bd2.kamezawa.hiroyu@jp.fujitsu.com> <20091210075454.GB25549@elte.hu> <20091210172040.37d259d3.kamezawa.hiroyu@jp.fujitsu.com> <20091210083310.GB6834@elte.hu> <20091210173819.GA5256@elte.hu> <20091210185459.GA8697@elte.hu> Organization: FUJITSU Co. LTD. X-Mailer: Sylpheed 2.5.0 (GTK+ 2.10.14; i686-pc-mingw32) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1539 Lines: 43 On Thu, 10 Dec 2009 19:54:59 +0100 Ingo Molnar wrote: > > [...] Exposing via perf is outside of the scope of his work. > > Please make thoughts about intelligent instrumentation solutions, and > please think "outside of the scope" of your usual routine. > I'm sorry that I don't fully understand your suggestion... This patch is for _usage_ counters (those can increase/decrease and can be modified in batched manner), but you don't talk about usage counter but about lack of (useful) _event_ counters under page fault path. If so, yes, I agree that current events are not enough. If not, hmm ? More event counters I can think of around mm/page-fault is following.. - fault to new anon pages + a new anon page is from remote node. - fault to file-backed area + a file page is from remote node. - copy_on_write + a new anon page is from remote node. + copy-on-write to zero page. - make page write (make page dirty) - search vma. (find_vma() is called and goes into rb-tree lookup) - swap-in (necessary ?) - get_user_page() is called to snoop other process's memory. I wonder adding event and inserting perf_sw_event(PERF_COUNT_SW....) is enough for adding event coutners...but is there good documentation of this hook ? Thanks, -Kame -- 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/