From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx172.postini.com [74.125.245.172]) by kanga.kvack.org (Postfix) with SMTP id AD5F36B015B for ; Wed, 1 May 2013 02:56:02 -0400 (EDT) Received: by mail-yh0-f41.google.com with SMTP id i57so246286yha.28 for ; Tue, 30 Apr 2013 23:56:01 -0700 (PDT) Message-ID: <5180BC79.8080101@gmail.com> Date: Wed, 01 May 2013 14:55:53 +0800 From: Mtrr Patt MIME-Version: 1.0 Subject: Re: Better active/inactive list balancing References: <517B6DF5.70402@gmail.com> <517B6E46.30209@gmail.com> <20130430163230.GB1229@cmpxchg.org> In-Reply-To: <20130430163230.GB1229@cmpxchg.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Johannes Weiner Cc: Rik van Riel , Dave Hansen , Michal Hocko , Mel Gorman , linux-mm@kvack.org Hi Johannes, On 05/01/2013 12:32 AM, Johannes Weiner wrote: > On Sat, Apr 27, 2013 at 02:20:54PM +0800, Mtrr Patt wrote: >> cc linux-mm >> >> On 04/27/2013 02:19 PM, Mtrr Patt wrote: >>> Hi Johannes, >>> >>> http://lwn.net/Articles/495543/ >>> >>> This link said that "When active pages are considered for >>> eviction, they are first moved to the inactive list and unmapped >> >from the address space of the process(es) using them. Thus, once a >>> page moves to the inactive list, any attempt to reference it will >>> generate a page fault; this "soft fault" will cause the page to be >>> removed back to the active list." >>> >>> Why I can't find the codes unmap during page moved from active >>> list to inactive list? > Most architectures have the hardware track the referenced bit in the > page tables, but some don't. For them, page_referenced_one() will > mark the mapping read-only when clearing the referenced/young bit and > the page fault handler will set the bit manually. Thanks for your response. ;-) So the article is not against more common case, isn't it? > When mapped pages reach the end of the inactive list and have that bit > set, they get activated, see page_check_references(). It seems that the page should trigger page fault twice and page_check_references can active it. -- 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