From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757712Ab2IDTkD (ORCPT ); Tue, 4 Sep 2012 15:40:03 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33078 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751967Ab2IDTkA (ORCPT ); Tue, 4 Sep 2012 15:40:00 -0400 Date: Tue, 4 Sep 2012 15:39:49 -0400 From: Vivek Goyal To: Mikulas Patocka Cc: Kent Overstreet , linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, tj@kernel.org, bharrosh@panasas.com, Jens Axboe Subject: Re: [PATCH v7 9/9] block: Avoid deadlocks with bio allocation by stacking drivers Message-ID: <20120904193949.GC2603@redhat.com> References: <1346175456-1572-10-git-send-email-koverstreet@google.com> <20120829165006.GB20312@google.com> <20120829170711.GC12504@redhat.com> <20120829171345.GC20312@google.com> <20120830220745.GI27257@redhat.com> <20120831014359.GB15218@moria.home.lan> <20120904034100.GA21602@moria.home.lan> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 04, 2012 at 03:26:19PM -0400, Mikulas Patocka wrote: [..] > BTW. can these new-style timerless plugs introduce deadlocks too? What > happens when some bios are indefinitely delayed because their requests are > held in a plug and a mempool runs out? I think they will not deadlock because these on stack bios/requests are flushed/dispatched when process schedules out. So if a submitter blocks on a mempool, it will be scheduled out and requests on plug will be dispatched. Thanks Vivek