From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Sender: Tejun Heo Date: Fri, 3 Mar 2017 11:12:22 -0800 From: Tejun Heo To: Hou Tao Cc: linux-block@vger.kernel.org, axboe@kernel.dk Subject: Re: [PATCH] block: use put_io_context_active() to disassociate bio from a task Message-ID: <20170303191222.GA20854@wtj.duckdns.org> References: <1488524470-570-1-git-send-email-houtao1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1488524470-570-1-git-send-email-houtao1@huawei.com> List-ID: Hello, On Fri, Mar 03, 2017 at 03:01:10PM +0800, Hou Tao wrote: > bio_associate_current() invokes get_io_context_active() to tell > CFQ scheduler that the current io_context is still issuing IOs > by increasing active_ref. When the bio is done, we also need > to invoke put_io_context_active() to decrease active_ref else > the associated io_context will always be active. > > Signed-off-by: Hou Tao Can you please explain how you noticed issue and verified the patch? Also, the patch will need the following. Fixes: 852c788f8365 ("block: implement bio_associate_current()") Cc: stable@vger.kernel.org # v3.5+ I think the failure mode isn't severe. We'll be carrying around ioc's longer than necessary but that's about it. I wonder whether the logic can be simplified in general. Anyways, please feel free to add Acked-by: Tejun Heo Thanks. -- tejun