From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 30 Nov 2006 21:18:41 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [RFC][PATCH 0/1] Node-based reclaim/migration Message-Id: <20061130211841.6f1fb0f3.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <6599ad830611300325h3269a185x5794b0c585d985c0@mail.gmail.com> References: <20061129030655.941148000@menage.corp.google.com> <20061130093105.d872c49d.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830611291631hd6d3e52y971c35708004db00@mail.gmail.com> <6599ad830611300245s5c0f40bdu4231832930e9c023@mail.gmail.com> <20061130201232.7d5f5578.kamezawa.hiroyu@jp.fujitsu.com> <6599ad830611300325h3269a185x5794b0c585d985c0@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Paul Menage Cc: clameter@sgi.com, linux-mm@kvack.org, akpm@osdl.org List-ID: On Thu, 30 Nov 2006 03:25:21 -0800 "Paul Menage" wrote: > On 11/30/06, KAMEZAWA Hiroyuki wrote: > > > > > How does kswapd do this safely? > > > > > kswapd doesn't touches page->mapping after page_mapcount() goes down to 0. > > OK, so we could do the same, and just assume that pages with a > page_mapcount() of 0 are either about to be freed or can be picked up > on a later migration sweep. Is it common for a page to have a 0 > page_mapcount() for a long period of time without being freed or > remapped? > see shrink_page_list(). unmap -> (write to swap) -> freed. depends on how long write-back needs. -Kame -- 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