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 64A656B0012 for ; Wed, 18 May 2011 14:25:59 -0400 (EDT) Received: from hpaq3.eem.corp.google.com (hpaq3.eem.corp.google.com [172.25.149.3]) by smtp-out.google.com with ESMTP id p4IIPplM017696 for ; Wed, 18 May 2011 11:25:51 -0700 Received: from pvc21 (pvc21.prod.google.com [10.241.209.149]) by hpaq3.eem.corp.google.com with ESMTP id p4IIPmJW025620 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NOT) for ; Wed, 18 May 2011 11:25:49 -0700 Received: by pvc21 with SMTP id 21so1202664pvc.11 for ; Wed, 18 May 2011 11:25:47 -0700 (PDT) Date: Wed, 18 May 2011 11:25:48 -0700 (PDT) From: Hugh Dickins Subject: Re: [PATCH mmotm] add the pagefault count into memcg stats: shmem fix In-Reply-To: <20110518144349.a44ae926.nishimura@mxp.nes.nec.co.jp> Message-ID: References: <20110518144349.a44ae926.nishimura@mxp.nes.nec.co.jp> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Daisuke Nishimura Cc: Andrew Morton , Ying Han , KAMEZAWA Hiroyuki , KOSAKI Motohiro , Minchan Kim , Balbir Singh , linux-mm@kvack.org On Wed, 18 May 2011, Daisuke Nishimura wrote: > On Tue, 17 May 2011 11:24:40 -0700 (PDT) > Hugh Dickins wrote: > > > mem_cgroup_count_vm_event() should update the PGMAJFAULT count for the > > target mm, not for current mm (but of course they're usually the same). > > > hmm, why ? > In shmem_getpage(), we charge the page to the memcg where current mm belongs to, (In the case when it's this fault which is creating the page. Just as when filemap_fault() reads in the page, add_to_page_cache will charge it to the current->mm's memcg, yes. Arguably correct.) > so I think counting vm events of the memcg is right. It should be consistent with which task gets the maj_flt++, and it should be consistent with filemap_fault(), and it should be a subset of what's counted by mem_cgroup_count_vm_event(mm, PGFAULT). In each case, those work on target mm rather than current->mm. Hugh -- 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