From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 28 Apr 2006 17:36:50 -0700 From: Andrew Morton Subject: Re: [PATCH 1/7] page migration: Reorder functions in migrate.c Message-Id: <20060428173650.146a6605.akpm@osdl.org> In-Reply-To: References: <20060428060302.30257.76871.sendpatchset@schroedinger.engr.sgi.com> <20060428150806.057b0bac.akpm@osdl.org> <20060428161830.7af8c3f0.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: linux-mm@kvack.org, kamezawa.hiroyu@jp.fujitsu.com, lee.schermerhorn@hp.com, hugh@veritas.com List-ID: hm. migrate_pages() locks two pages at the same time. We've avoided doing that. a) what prevents ab/ba deadlocks in the migration code? b) if some other part of the kernel later decides to lock two pages at the same time, what protocol should that code follow to avoid ab/ba deadlocks? lowest-pfn-first might be one. -- 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