From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754287AbZEDIF2 (ORCPT ); Mon, 4 May 2009 04:05:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752875AbZEDIFL (ORCPT ); Mon, 4 May 2009 04:05:11 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:53063 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752484AbZEDIFJ (ORCPT ); Mon, 4 May 2009 04:05:09 -0400 Subject: Re: [PATCH] vmscan: evict use-once pages first (v2) From: Peter Zijlstra To: Andrew Morton Cc: Rik van Riel , elladan@eskimo.com, linux-kernel@vger.kernel.org, tytso@mit.edu, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org In-Reply-To: <20090501123541.7983a8ae.akpm@linux-foundation.org> References: <20090428044426.GA5035@eskimo.com> <20090428192907.556f3a34@bree.surriel.com> <1240987349.4512.18.camel@laptop> <20090429114708.66114c03@cuia.bos.redhat.com> <20090430072057.GA4663@eskimo.com> <20090430174536.d0f438dd.akpm@linux-foundation.org> <20090430205936.0f8b29fc@riellaptop.surriel.com> <20090430181340.6f07421d.akpm@linux-foundation.org> <20090430215034.4748e615@riellaptop.surriel.com> <20090430195439.e02edc26.akpm@linux-foundation.org> <49FB01C1.6050204@redhat.com> <20090501123541.7983a8ae.akpm@linux-foundation.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Mon, 04 May 2009 10:04:37 +0200 Message-Id: <1241424277.7620.4491.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.26.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2009-05-01 at 12:35 -0700, Andrew Morton wrote: > No, I think it still _is_ the case. When reclaim is treating mapped > and non-mapped pages equally, the end result sucks. Applications get > all laggy and humans get irritated. It may be that the system was > optimised from an overall throughput POV, but the result was > *irritating*. > > Which led us to prefer to retain mapped pages. This had nothing at all > to do with internal impementation details - it was a design objective > based upon empirical observation of system behaviour. Shouldn't we make a distinction between PROT_EXEC and other mappings in this? Because as soon as you're running an application that uses gobs and gobs of mmap'ed memory, the mapped vs non-mapped thing breaks down. 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 ESMTP id 799816B0055 for ; Mon, 4 May 2009 04:04:48 -0400 (EDT) Subject: Re: [PATCH] vmscan: evict use-once pages first (v2) From: Peter Zijlstra In-Reply-To: <20090501123541.7983a8ae.akpm@linux-foundation.org> References: <20090428044426.GA5035@eskimo.com> <20090428192907.556f3a34@bree.surriel.com> <1240987349.4512.18.camel@laptop> <20090429114708.66114c03@cuia.bos.redhat.com> <20090430072057.GA4663@eskimo.com> <20090430174536.d0f438dd.akpm@linux-foundation.org> <20090430205936.0f8b29fc@riellaptop.surriel.com> <20090430181340.6f07421d.akpm@linux-foundation.org> <20090430215034.4748e615@riellaptop.surriel.com> <20090430195439.e02edc26.akpm@linux-foundation.org> <49FB01C1.6050204@redhat.com> <20090501123541.7983a8ae.akpm@linux-foundation.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Mon, 04 May 2009 10:04:37 +0200 Message-Id: <1241424277.7620.4491.camel@twins> Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: Rik van Riel , elladan@eskimo.com, linux-kernel@vger.kernel.org, tytso@mit.edu, kosaki.motohiro@jp.fujitsu.com, linux-mm@kvack.org List-ID: On Fri, 2009-05-01 at 12:35 -0700, Andrew Morton wrote: > No, I think it still _is_ the case. When reclaim is treating mapped > and non-mapped pages equally, the end result sucks. Applications get > all laggy and humans get irritated. It may be that the system was > optimised from an overall throughput POV, but the result was > *irritating*. > > Which led us to prefer to retain mapped pages. This had nothing at all > to do with internal impementation details - it was a design objective > based upon empirical observation of system behaviour. Shouldn't we make a distinction between PROT_EXEC and other mappings in this? Because as soon as you're running an application that uses gobs and gobs of mmap'ed memory, the mapped vs non-mapped thing breaks down. -- 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