From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Elder Subject: Re: krbd blk-mq support ? Date: Tue, 28 Oct 2014 17:31:12 -0500 Message-ID: <54501930.7070405@ieee.org> References: <20141027094556.GA31604@infradead.org> <20141028180725.GA1138@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pd0-f169.google.com ([209.85.192.169]:36287 "EHLO mail-pd0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755046AbaJ1WbQ (ORCPT ); Tue, 28 Oct 2014 18:31:16 -0400 Received: by mail-pd0-f169.google.com with SMTP id y10so1634721pdj.28 for ; Tue, 28 Oct 2014 15:31:15 -0700 (PDT) In-Reply-To: <20141028180725.GA1138@infradead.org> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Christoph Hellwig , Alexandre DERUMIER Cc: Ceph Devel On 10/28/2014 01:07 PM, Christoph Hellwig wrote: > On Mon, Oct 27, 2014 at 11:00:46AM +0100, Alexandre DERUMIER wrote: >>>> Can you do a perf report -ag and then a perf report to see where these >>>> cycles are spent? >> >> Yes, sure. >> >> I have attached the perf report to this mail. >> (This is with kernel 3.14, don't have access to my 3.18 host for now) > > Oh, that's without the blk-mq patch? > > Either way the profile doesn't really sum up to a fully used up > cpu. Sage, Alex - are there any ordring constraints in the rbd client? I don't remember off hand. In libceph I recall going to great lengths to retain the original order of requests when they got re-sent after a connection reset. I'll go look at the code a bit and see if I can refresh my memory (though Sage may answer before I do). -Alex > If not we could probably aim for per-cpu queues using blk-mq and a > socket per cpu or similar. > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >