From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759699AbXJDJvR (ORCPT ); Thu, 4 Oct 2007 05:51:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755308AbXJDJvF (ORCPT ); Thu, 4 Oct 2007 05:51:05 -0400 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:52692 "EHLO amd.ucw.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754500AbXJDJvC (ORCPT ); Thu, 4 Oct 2007 05:51:02 -0400 Date: Thu, 4 Oct 2007 11:49:20 +0200 From: Pavel Machek To: Andrew Morton , kernel list Subject: vm.txt: document min_free_pages as critical for correctness Message-ID: <20071004094920.GA407@elf.ucw.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.16 (2007-06-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org min_free_pages is critical for correctness, document it as such. Signed-off-by: Pavel Machek index a0ccc5b..e460c19 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -111,6 +111,12 @@ of kilobytes free. The VM uses this num value for each lowmem zone in the system. Each lowmem zone gets a number of reserved free pages based proportionally on its size. +Some minimal ammount of memory is needed to satisfy PF_MEMALLOC +allocations; if you set this to lower than 1024KB, your system will +become subtly broken, and prone to deadlock under high loads. + +Setting this too high will OOM your machine instantly. + ============================================================== percpu_pagelist_fraction -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html