Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933802Ab2JaCIo (ORCPT ); Tue, 30 Oct 2012 22:08:44 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50826 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932069Ab2JaCIm (ORCPT ); Tue, 30 Oct 2012 22:08:42 -0400 MIME-Version: 1.0 In-Reply-To: <2504263.kbM6W9JoH9@linux-lqwf.site> References: <2504263.kbM6W9JoH9@linux-lqwf.site> Date: Wed, 31 Oct 2012 10:08:40 +0800 Message-ID: Subject: Re: [PATCH v3 2/6] PM / Runtime: introduce pm_runtime_set[get]_memalloc_noio() From: Ming Lei To: Oliver Neukum Cc: Alan Stern , linux-kernel@vger.kernel.org, Minchan Kim , Greg Kroah-Hartman , "Rafael J. Wysocki" , Jens Axboe , "David S. Miller" , Andrew Morton , netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-pm@vger.kernel.org, linux-mm@kvack.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 987 Lines: 23 On Wed, Oct 31, 2012 at 12:30 AM, Oliver Neukum wrote: >> If the USB mass-storage device is being reseted, the flag should be set >> already generally. If the flag is still unset, that means the disk/network >> device isn't added into system(or removed just now), so memory allocation >> with block I/O should be allowed during the reset. Looks it isn't one problem, >> isn't it? > > I am afraid it is, because a disk may just have been probed as the deviceis being reset. Yes, it is probable, and sounds like similar with 'root_wait' problem, see prepare_namespace(): init/do_mounts.c, so looks no good solution for the problem, and maybe we have to set the flag always before resetting usb device. Thanks, -- Ming Lei -- 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/