From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [RFC] writeback and cgroup Date: Fri, 20 Apr 2012 14:33:01 -0700 Message-ID: <20120420213301.GA29134__40344.1534414471$1334957600$gmane$org@google.com> References: <20120403183655.GA23106@dhcp-172-17-108-109.mtv.corp.google.com> <20120404175124.GA8931@localhost> <20120404193355.GD29686@dhcp-172-17-108-109.mtv.corp.google.com> <20120406095934.GA10465@localhost> <20120417223854.GG19975@google.com> <20120419142343.GA12684@localhost> <20120419183118.GM10216@redhat.com> <20120420124518.GA7133@localhost> <20120420192930.GR22419@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20120420192930.GR22419-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Vivek Goyal Cc: Jens Axboe , ctalbott-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, Jan Kara , rni-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, andrea-oIIqvOZpAevzfdHfmsDf5w@public.gmane.org, containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, sjayaraman-IBi9RG/b67k@public.gmane.org, lsf-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, jmoyer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Fengguang Wu List-Id: containers.vger.kernel.org On Fri, Apr 20, 2012 at 03:29:30PM -0400, Vivek Goyal wrote: > I am personally is not too excited about the case of putting async IO > in separate groups due to the reason that async IO of one group will > start impacting latencies of sync IO of another group and in practice > it might not be desirable. But there are others who have use cases for > separate async IO queue. So as long as switch is there to change the > behavior, I am not too worried. Why not just fix cfq so that it prefers groups w/ sync IOs? -- tejun