Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759028Ab0GIAqg (ORCPT ); Thu, 8 Jul 2010 20:46:36 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:35138 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758768Ab0GIAqf (ORCPT ); Thu, 8 Jul 2010 20:46:35 -0400 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Christoph Lameter Subject: Re: [PATCH v2 2/2] vmscan: shrink_slab() require number of lru_pages, not page order Cc: kosaki.motohiro@jp.fujitsu.com, Andrew Morton , LKML , linux-mm , Mel Gorman , Rik van Riel , Minchan Kim , Johannes Weiner In-Reply-To: References: <20100708133152.5e556508.akpm@linux-foundation.org> Message-Id: <20100709092124.CD5A.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Fri, 9 Jul 2010 09:46:32 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1828 Lines: 48 > On Thu, 8 Jul 2010, Andrew Morton wrote: > > > > AFAICT this is not argument error but someone changed the naming of the > > > parameter. > > > > It's been there since day zero: > > > > : commit 2a16e3f4b0c408b9e50297d2ec27e295d490267a > > : Author: Christoph Lameter > > : AuthorDate: Wed Feb 1 03:05:35 2006 -0800 > > : Commit: Linus Torvalds > > : CommitDate: Wed Feb 1 08:53:16 2006 -0800 > > : > > : [PATCH] Reclaim slab during zone reclaim > > That only shows that the order parameter was passed to shrink_slab() which > is what I remember being done intentionally. > > Vaguely recall that this was necessary to avoid shrink_slab() throwing out > too many pages for higher order allocs. But It make opposite effect. number of scanning objects of shrink_slab() are lru_scanned max_pass basic_scan_objects = 4 x ------------- x ----------------------------- lru_pages shrinker->seeks (default:2) scan_objects = min(basic_scan_objects, max_pass * 2) That said, small lru_pages parameter makes too many slab dropping. Practically, zone-reclaim always take max_pass*2. about inode, shrink_icache_memory() takes number of unused inode as max_pass. It mean one shrink_slab() calling drop all icache. Is this optimal behavior? why? Am I missing something? > Initially zone_reclaim was full of heuristics that later were replaced by > counter as the new ZVCs became available and gradually better ways of > accounting for pages became possible. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/