From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id D2F766B004D for ; Thu, 23 Jul 2009 07:43:33 -0400 (EDT) Date: Thu, 23 Jul 2009 12:43:25 +0100 (BST) From: Hugh Dickins Subject: Re: [PATCH 06/10] ksm: identify PageKsm pages In-Reply-To: <20090723110655.f08cdcdc.kamezawa.hiroyu@jp.fujitsu.com> Message-ID: References: <1247851850-4298-1-git-send-email-ieidus@redhat.com> <1247851850-4298-2-git-send-email-ieidus@redhat.com> <1247851850-4298-3-git-send-email-ieidus@redhat.com> <1247851850-4298-4-git-send-email-ieidus@redhat.com> <1247851850-4298-5-git-send-email-ieidus@redhat.com> <1247851850-4298-6-git-send-email-ieidus@redhat.com> <1247851850-4298-7-git-send-email-ieidus@redhat.com> <20090721175139.GE2239@random.random> <4A660101.3000307@redhat.com> <20090723110655.f08cdcdc.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: KAMEZAWA Hiroyuki Cc: Rik van Riel , Andrea Arcangeli , Izik Eidus , akpm@linux-foundation.org, chrisw@redhat.com, avi@redhat.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, nickpiggin@yahoo.com.au, Wu Fengguang List-ID: On Thu, 23 Jul 2009, KAMEZAWA Hiroyuki wrote: > On Wed, 22 Jul 2009 13:54:06 +0100 (BST) > Hugh Dickins wrote: > > > > (At this instant I've forgotten why there's an unevictable list at > > all - somewhere in vmscan.c which is accustomed to dealing with > > pages on lists, so easier to have them on a list than not?) > > > I forget, too. But in short thinking, Unevictable pages should be > on LRU (marked as PG_lru) for isolating page (from LRU) called by > page migration etc. > > isolate_lru_page() > -> put page on private list > -> do some work > -> putback_lru_page() > > sequence is useful at handling pages in a list. > Because mlock/munclock can be called arbitrarily, unevicatable lru > works enough good for making above kinds of code simpler. Yes, I think that's it, thanks. And for the moment, the KSM pages are therefore unmigratable as well as unswappable; but that should change in 2.6.33. 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/ . Don't email: email@kvack.org