From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id BE21B6B01F9 for ; Wed, 18 Aug 2010 15:34:56 -0400 (EDT) Date: Wed, 18 Aug 2010 15:34:40 -0400 From: Chris Mason Subject: Re: [PATCH] VM: kswapd should not do blocking memory allocations Message-ID: <20100818193440.GZ5854@think> References: <1282158241.8540.85.camel@heimdal.trondhjem.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1282158241.8540.85.camel@heimdal.trondhjem.org> Sender: owner-linux-mm@kvack.org To: Trond Myklebust Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org List-ID: On Wed, Aug 18, 2010 at 03:04:01PM -0400, Trond Myklebust wrote: > From: Trond Myklebust > > Allowing kswapd to do GFP_KERNEL memory allocations (or any blocking memory > allocations) is wrong and can cause deadlocks in try_to_release_page(), as > the filesystem believes it is safe to allocate new memory and block, > whereas kswapd is there specifically to clear a low-memory situation... > > Set the gfp_mask to GFP_IOFS instead. I always thought releasepage was supposed to do almost zero work. It could release an instantly freeable page but it wasn't supposed to dive in and solve world hunger or anything. I thought the VM would be using writepage for that. -chris -- 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