From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754286Ab1HVXia (ORCPT ); Mon, 22 Aug 2011 19:38:30 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:46209 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751589Ab1HVXi2 (ORCPT ); Mon, 22 Aug 2011 19:38:28 -0400 Date: Mon, 22 Aug 2011 16:38:21 -0700 From: Andrew Morton To: Dave Chinner Cc: Konstantin Khlebnikov , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] vmscan: fix initial shrinker size handling Message-Id: <20110822163821.e746ab25.akpm@linux-foundation.org> In-Reply-To: <20110822232257.GT3162@dastard> References: <20110822101721.19462.63082.stgit@zurg> <20110822232257.GT3162@dastard> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 23 Aug 2011 09:22:57 +1000 Dave Chinner wrote: > On Mon, Aug 22, 2011 at 02:17:21PM +0300, Konstantin Khlebnikov wrote: > > Shrinker function can returns -1, it means it cannot do anything without a risk of deadlock. > > For example prune_super() do this if it cannot grab superblock refrence, even if nr_to_scan=0. > > Currenly we interpret this like ULONG_MAX size shrinker, evaluate total_scan according this, > > and next time this shrinker can get really big pressure. Let's skip such shrinkers instead. > > > > Also make total_scan signed, otherwise check (total_scan < 0) below never works. > > I've got a patch set I am going to post out today that makes this > irrelevant. Well, how serious is the bug? If it's a non-issue then we can leave the fix until 3.1. If it's a non-non-issue then we'd need a minimal patch to fix up 3.1 and 3.0.x. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta8.messagelabs.com (mail6.bemta8.messagelabs.com [216.82.243.55]) by kanga.kvack.org (Postfix) with ESMTP id 6BAF76B016A for ; Mon, 22 Aug 2011 19:38:26 -0400 (EDT) Date: Mon, 22 Aug 2011 16:38:21 -0700 From: Andrew Morton Subject: Re: [PATCH 1/2] vmscan: fix initial shrinker size handling Message-Id: <20110822163821.e746ab25.akpm@linux-foundation.org> In-Reply-To: <20110822232257.GT3162@dastard> References: <20110822101721.19462.63082.stgit@zurg> <20110822232257.GT3162@dastard> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Dave Chinner Cc: Konstantin Khlebnikov , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Tue, 23 Aug 2011 09:22:57 +1000 Dave Chinner wrote: > On Mon, Aug 22, 2011 at 02:17:21PM +0300, Konstantin Khlebnikov wrote: > > Shrinker function can returns -1, it means it cannot do anything without a risk of deadlock. > > For example prune_super() do this if it cannot grab superblock refrence, even if nr_to_scan=0. > > Currenly we interpret this like ULONG_MAX size shrinker, evaluate total_scan according this, > > and next time this shrinker can get really big pressure. Let's skip such shrinkers instead. > > > > Also make total_scan signed, otherwise check (total_scan < 0) below never works. > > I've got a patch set I am going to post out today that makes this > irrelevant. Well, how serious is the bug? If it's a non-issue then we can leave the fix until 3.1. If it's a non-non-issue then we'd need a minimal patch to fix up 3.1 and 3.0.x. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org