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 BCECA6B0047 for ; Tue, 23 Feb 2010 09:44:28 -0500 (EST) Received: by bwz19 with SMTP id 19so3010297bwz.6 for ; Tue, 23 Feb 2010 06:44:26 -0800 (PST) Subject: Re: [patch 1/3] vmscan: factor out page reference checks From: Minchan Kim In-Reply-To: <20100223142158.GA29762@cmpxchg.org> References: <1266868150-25984-1-git-send-email-hannes@cmpxchg.org> <1266868150-25984-2-git-send-email-hannes@cmpxchg.org> <1266932303.2723.13.camel@barrios-desktop> <20100223142158.GA29762@cmpxchg.org> Content-Type: text/plain; charset="UTF-8" Date: Tue, 23 Feb 2010 23:44:14 +0900 Message-ID: <1266936254.2723.33.camel@barrios-desktop> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Johannes Weiner Cc: Andrew Morton , KOSAKI Motohiro , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Tue, 2010-02-23 at 15:21 +0100, Johannes Weiner wrote: > Hello Minchan, > > On Tue, Feb 23, 2010 at 10:38:23PM +0900, Minchan Kim wrote: > > > > > > if (PageDirty(page)) { > > > - if (sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced) > > > + if (references == PAGEREF_RECLAIM_CLEAN) > > > > How equal PAGEREF_RECLAIM_CLEAN and sc->order <= PAGE_ALLOC_COSTLY_ORDER > > && referenced by semantic? > > It is encoded in page_check_references(). When > sc->order <= PAGE_ALLOC_COSTLY_ORDER && referenced > it returns PAGEREF_RECLAIM_CLEAN. > > So > > - PageDirty() && order < COSTLY && referenced > + PageDirty() && references == PAGEREF_RECLAIM_CLEAN > > is an equivalent transformation. Does this answer your question? Hmm. I knew it. My point was PAGEREF_RECLAIM_CLEAN seems to be a little awkward. I thought PAGEREF_RECLAIM_CLEAN means if the page was clean, it can be reclaimed. I think it would be better to rename it with represent "Although it's referenced page recently, we can reclaim it if VM try to reclaim high order page". > > Hannes -- Kind regards, Minchan Kim -- 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