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 SMTP id 68A8C6B0105 for ; Thu, 28 Oct 2010 23:43:23 -0400 (EDT) Message-ID: <4CCA42D0.5090603@redhat.com> Date: Thu, 28 Oct 2010 23:43:12 -0400 From: Rik van Riel MIME-Version: 1.0 Subject: Re: [PATCH] mm: don't flush TLB when propagate PTE access bit to struct page. References: <1288200090-23554-1-git-send-email-yinghan@google.com> <4CC869F5.2070405@redhat.com> <20101028091158.4de545e9.kamezawa.hiroyu@jp.fujitsu.com> <20101029114529.4d3a8b9c.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20101029114529.4d3a8b9c.kamezawa.hiroyu@jp.fujitsu.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Ken Chen , Ying Han , Hugh Dickins , Nick Piggin , linux-mm@kvack.org, Minchan Kim , Andrew Morton List-ID: On 10/28/2010 10:45 PM, KAMEZAWA Hiroyuki wrote: > Hmm. Without flushing anywhere in memory reclaim path, a process which > cause page fault and enter vmscan will not see his own recent access bit on > pages in LRU ? Worse still, because kernel threads do a lazy mmu switch, even page faulting in the process will not cause the TLB entries to be flushed. > I think it should be flushed at least once.. A periodic flush may make sense. Maybe something along the lines of if the TLB has not been flushed for over a second (we can see that in timer or scheduler code), flush it? -- All rights reversed -- 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/ . Don't email: email@kvack.org