Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753485Ab2JONVQ (ORCPT ); Mon, 15 Oct 2012 09:21:16 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:39902 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753353Ab2JONVP (ORCPT ); Mon, 15 Oct 2012 09:21:15 -0400 MIME-Version: 1.0 In-Reply-To: <1921559.OPsFBnvatA@linux-lqwf.site> References: <1350278059-14904-1-git-send-email-ming.lei@canonical.com> <2564763.3cNFlv543H@linux-lqwf.site> <1921559.OPsFBnvatA@linux-lqwf.site> Date: Mon, 15 Oct 2012 21:21:13 +0800 Message-ID: Subject: Re: [RFC PATCH 3/3] USB: forbid memory allocation with I/O during bus reset if storage interface exits From: Ming Lei To: Oliver Neukum Cc: linux-kernel@vger.kernel.org, Greg Kroah-Hartman , linux-usb@vger.kernel.org, Alan Stern 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: 1221 Lines: 36 On Mon, Oct 15, 2012 at 8:30 PM, Oliver Neukum wrote: > > All network devices? Good point, but I am wondering if there are guys who would like to bring up iSCSI over usb network dongle, which should be very slow at least with high speed. For super speed device, looks there are few network dongles in market now. So how about keeping the limit now? We can remove the limit or extend it to network device if there are some USB 3.0 network dongles coming. > >> > we will see busses attached to busses and as soon as the daughter >> > bus is hotpluggable you are thwarted anyway. Just do it unconditionally. >> >> IMO, doing it unconditionally is not good because big chunk buffer >> is often allocated in probe() path. > > It would be a chunk that has just been freed. The reset will last for a bit long time, and many memory allocations are involved inside usb_reset_and_verify_device(), so it might be hard to get the previous chunk. Thanks, -- Ming -- 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/