From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751668AbWCUNNS (ORCPT ); Tue, 21 Mar 2006 08:13:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751669AbWCUNNR (ORCPT ); Tue, 21 Mar 2006 08:13:17 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:3718 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S1751666AbWCUNNR (ORCPT ); Tue, 21 Mar 2006 08:13:17 -0500 Subject: Re: [PATCH][8/8] mm: lru interface change From: Arjan van de Ven To: Nick Piggin Cc: Stone Wang , akpm@osdl.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org In-Reply-To: <441FF007.6020901@yahoo.com.au> References: <441FF007.6020901@yahoo.com.au> Content-Type: text/plain Date: Tue, 21 Mar 2006 14:13:05 +0100 Message-Id: <1142946785.3077.78.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > + page->wired_count ++; > > Oh dear, I missed this change you made to struct page, tucked away in 5/8. > This alone pretty much makes it a showstopper, I'm afraid. You'll have to > work out some other way to do it so as not to penalise 99.999% of machines > which don't need this. > > (Oh, and making the field a short usually won't help either, because of > alignment constraints). it's not that hard even. All you need to do is make the vm be lazy about it; if it encounters a pinned page during scanning, move it THEN to the pinned list. If it then gets pinned more no issue. The first unpin then moves it back to the normal list (yes it's still pinned), but the first time the VM sees it it goes right back to the pinned list. That way there's no need to keep a "pin depth" at all...