From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47944) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ePERN-0000b6-TJ for qemu-devel@nongnu.org; Wed, 13 Dec 2017 16:19:46 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ePERJ-00026g-Up for qemu-devel@nongnu.org; Wed, 13 Dec 2017 16:19:45 -0500 Sender: Paolo Bonzini References: <20171213204611.26276-1-jsnow@redhat.com> From: Paolo Bonzini Message-ID: <4ca12a05-2e7b-9c39-d32d-ec3e3febead1@redhat.com> Date: Wed, 13 Dec 2017 22:19:37 +0100 MIME-Version: 1.0 In-Reply-To: <20171213204611.26276-1-jsnow@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2] blockjob: kick jobs on set-speed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: John Snow , qemu-block@nongnu.org Cc: kwolf@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com, stefanha@redhat.com On 13/12/2017 21:46, John Snow wrote: > > When a user provides a new speed, kick the job to allow it to recalculate > its delay. > > Signed-off-by: John Snow > --- > > RFC: Why is block_job_mutex shared between all jobs, > instead of being per-job? Because that patch was partly extracted out of a bigger one, and I was both lazy and worried about breaking things close to the release. In other words more uses of the mutex are coming, and it will need to be shared between jobs to work fine with transactions and monitor commands (which don't know the job they're working on until they've looked it up). Starting a paused block job is not a hot path. :) Paolo