From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754013Ab2DMSNI (ORCPT ); Fri, 13 Apr 2012 14:13:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12136 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750966Ab2DMSNE (ORCPT ); Fri, 13 Apr 2012 14:13:04 -0400 Date: Fri, 13 Apr 2012 14:12:57 -0400 From: Vivek Goyal To: Tejun Heo Cc: axboe@kernel.dk, ctalbott@google.com, rni@google.com, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, containers@lists.linux-foundation.org Subject: Re: [PATCH 7/8] blkcg: implement per-queue policy activation Message-ID: <20120413181257.GG26383@redhat.com> References: <1334273380-30233-1-git-send-email-tj@kernel.org> <1334273380-30233-8-git-send-email-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1334273380-30233-8-git-send-email-tj@kernel.org> 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 Thu, Apr 12, 2012 at 04:29:39PM -0700, Tejun Heo wrote: [..] > diff --git a/block/elevator.c b/block/elevator.c > index be3ab6d..6a55d41 100644 > --- a/block/elevator.c > +++ b/block/elevator.c > @@ -896,8 +896,6 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e) > ioc_clear_queue(q); > spin_unlock_irq(q->queue_lock); > > - blkg_destroy_all(q, false); > - So now groups don't reclaimed until either cgroup is deleted or queue exits. So if BLK_DEV_THROTTLE=n and cfq is switched out, blkg created by CFQ policy will not be reclaimed (despite the fact nobody is using them). This is not necessarily bad, just thought of clarifying that it is the design intent. Thanks Vivek