From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx196.postini.com [74.125.245.196]) by kanga.kvack.org (Postfix) with SMTP id 145396B0068 for ; Wed, 19 Dec 2012 12:59:08 -0500 (EST) Date: Wed, 19 Dec 2012 12:58:11 -0500 From: Johannes Weiner Subject: Re: [patch 7/7] mm: reduce rmap overhead for ex-KSM page copies created on swap faults Message-ID: <20121219175811.GD7147@cmpxchg.org> References: <1355767957-4913-1-git-send-email-hannes@cmpxchg.org> <1355767957-4913-8-git-send-email-hannes@cmpxchg.org> <1355900479.1381.1.camel@kernel-VirtualBox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1355900479.1381.1.camel@kernel-VirtualBox> Sender: owner-linux-mm@kvack.org List-ID: To: Simon Jeons Cc: Andrew Morton , Rik van Riel , Michal Hocko , Mel Gorman , Hugh Dickins , Satoru Moriya , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, Dec 19, 2012 at 02:01:19AM -0500, Simon Jeons wrote: > On Mon, 2012-12-17 at 13:12 -0500, Johannes Weiner wrote: > > When ex-KSM pages are faulted from swap cache, the fault handler is > > not capable of re-establishing anon_vma-spanning KSM pages. In this > > case, a copy of the page is created instead, just like during a COW > > break. > > > > These freshly made copies are known to be exclusive to the faulting > > VMA and there is no reason to go look for this page in parent and > > sibling processes during rmap operations. > > > > Use page_add_new_anon_rmap() for these copies. This also puts them on > > the proper LRU lists and marks them SwapBacked, so we can get rid of > > doing this ad-hoc in the KSM copy code. > > Is it just a code cleanup instead of reduce rmap overhead? Both. -- 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