From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756227AbaIQSbE (ORCPT ); Wed, 17 Sep 2014 14:31:04 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:40868 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755656AbaIQSbD (ORCPT ); Wed, 17 Sep 2014 14:31:03 -0400 Date: Wed, 17 Sep 2014 14:30:49 -0400 From: Johannes Weiner To: Mel Gorman Cc: Andrew Morton , Rik van Riel , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: page_alloc: Make paranoid check in move_freepages a VM_BUG_ON Message-ID: <20140917183049.GB32607@cmpxchg.org> References: <20140909145228.GB12309@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140909145228.GB12309@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 09, 2014 at 03:52:28PM +0100, Mel Gorman wrote: > Since 2.6.24 there has been a paranoid check in move_freepages that looks > up the zone of two pages. This is a very slow path and the only time I've > seen this bug trigger recently is when memory initialisation was broken > during patch development. Despite the fact it's a slow path, this patch > converts the check to a VM_BUG_ON anyway as it is served its purpose by now. > > Signed-off-by: Mel Gorman Acked-by: Johannes Weiner