From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] Block: use a freezable workqueue for disk-event polling Date: Fri, 17 Feb 2012 13:52:04 -0800 Message-ID: <20120217215204.GH29414@google.com> References: <20120216102728.230b99ba@poochiereds.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pw0-f46.google.com ([209.85.160.46]:34836 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751310Ab2BQVwJ (ORCPT ); Fri, 17 Feb 2012 16:52:09 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Alan Stern Cc: "Rafael J. Wysocki" , Jens Axboe , Steve French , Chris Ball , Jeff Layton , David Airlie , David Howells , Linux-pm mailing list , linux-cifs@vger.kernel.org, linux-mmc@vger.kernel.org, dri-devel@lists.freedesktop.org, keyrings@linux-nfs.org On Fri, Feb 17, 2012 at 04:22:13PM -0500, Alan Stern wrote: > This patch (as1519) fixes a bug in the block layer's disk-events > polling. The polling is done by a work routine queued on the > system_nrt_wq workqueue. Since that workqueue isn't freezable, the > polling continues even in the middle of a system sleep transition. > > Obviously, polling a suspended drive for media changes and such isn't > a good thing to do; in the case of USB mass-storage devices it can > lead to real problems requiring device resets and even re-enumeration. > > The patch fixes things by creating a new system-wide, non-reentrant, > freezable workqueue and using it for disk-events polling. > > Signed-off-by: Alan Stern > CC: Tejun Heo > CC: Acked-by: Tejun Heo Thanks! -- tejun