From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932615Ab2IDTBT (ORCPT ); Tue, 4 Sep 2012 15:01:19 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:57451 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757530Ab2IDTBS (ORCPT ); Tue, 4 Sep 2012 15:01:18 -0400 Date: Tue, 4 Sep 2012 12:01:19 -0700 From: Tejun Heo To: Kent Overstreet Cc: Mikulas Patocka , Vivek Goyal , linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, dm-devel@redhat.com, bharrosh@panasas.com, Jens Axboe Subject: Re: [PATCH v7 9/9] block: Avoid deadlocks with bio allocation by stacking drivers Message-ID: <20120904190119.GD3638@dhcp-172-17-108-109.mtv.corp.google.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> <20120904185540.GC3638@dhcp-172-17-108-109.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120904185540.GC3638@dhcp-172-17-108-109.mtv.corp.google.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 04, 2012 at 11:55:40AM -0700, Tejun Heo wrote: > Actually, if the timer approach can reduce the frequency of rescuer > involvement, I think it could actually be better. Ooh, it wouldn't. It's kicking in only after alloc failure. I don't know. I think conditioning it on alloc failure is cleaner and converting all per-bio allocations to front-pad makes sense. Using a timer wouldn't make the mechanism any simpler, right? Thanks. -- tejun