Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423262AbXBUWys (ORCPT ); Wed, 21 Feb 2007 17:54:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1423260AbXBUWyr (ORCPT ); Wed, 21 Feb 2007 17:54:47 -0500 Received: from smtp.osdl.org ([65.172.181.24]:54451 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423258AbXBUWyq (ORCPT ); Wed, 21 Feb 2007 17:54:46 -0500 Date: Wed, 21 Feb 2007 14:54:19 -0800 From: Andrew Morton To: Alan Stern Cc: OGAWA Hirofumi , , Pete Zaitcev , Greg KH , Kumar Gala , Linux Kernel list Subject: Re: [linux-usb-devel] 2.6.20 kernel hang with USB drive and vfat doing ftruncate Message-Id: <20070221145419.2f783dc3.akpm@linux-foundation.org> In-Reply-To: References: <20070221133112.aec2bdac.akpm@linux-foundation.org> X-Mailer: Sylpheed version 2.2.7 (GTK+ 2.8.6; i686-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 X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 810 Lines: 19 On Wed, 21 Feb 2007 16:50:23 -0500 (EST) Alan Stern wrote: > > + if ((gfp_mask & (__GFP_FS|__GFP_IO)) != (__GFP_FS|__GFP_IO)) { > > Is that really the correct test? I don't know enough about the memory > management subsystem to say one way or the other. What's special about > having both flags set? yup. We're saying "if the caller is unable to take either IO locks or FS locks, don't wait on FS or IO completion". ie: don't wait on writeout progress unless we know that both the IO system and the FS are able to make progress. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/