From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Gordeev Subject: Re: [PATCH RESEND 0/1] AHCI: Optimize interrupt processing Date: Fri, 12 Jul 2013 09:46:00 +0200 Message-ID: <20130712074559.GA8727@dhcp-26-207.brq.redhat.com> References: <20130521235003.GE6985@mtj.dyndns.org> <20130522143923.GD19383@dhcp-26-207.brq.redhat.com> <20130522170305.GD9563@kernel.dk> <20130711102630.GA11133@dhcp-26-207.brq.redhat.com> <1373583637.7397.370.camel@haakon3.risingtidesystems.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:10640 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753027Ab3GLHo2 (ORCPT ); Fri, 12 Jul 2013 03:44:28 -0400 Content-Disposition: inline In-Reply-To: <1373583637.7397.370.camel@haakon3.risingtidesystems.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: "Nicholas A. Bellinger" Cc: Tejun Heo , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Jeff Garzik , Jens Axboe On Thu, Jul 11, 2013 at 04:00:37PM -0700, Nicholas A. Bellinger wrote: > On Thu, 2013-07-11 at 12:26 +0200, Alexander Gordeev wrote: > > On Wed, May 22, 2013 at 07:03:05PM +0200, Jens Axboe wrote: > > > On Wed, May 22 2013, Alexander Gordeev wrote: > > > > On Wed, May 22, 2013 at 08:50:03AM +0900, Tejun Heo wrote: > > > > > Hmmmmmm..... I'd normally apply this patch but block layer is just > > > > > growing multi-queue support and libata is likely to be converted to mq > > > > > in foreseeable future, so I'm a bit hesitant to make irq handling more > > > > > sophiscated right now. Would you be interested in looking into > > > > > converting libata to blk mq support? I'm pretty sure it'd yield far > > > > > better outcome if done properly. > > > > > > > > I am not committing, but will look into it, sure. > > > > > > Would be most awesome, I'm sure Nic would not mind a bit of help on the > > > SCSI/libata side :-) > > > > Hi Nicholas, > > > > Could you please clarify the status of SCSI MQ support? Is it usable now? > > > > Hi Alexander, > > Thanks for taking a look. I've not made further progress in the last > weeks on scsi-mq, but am still using virtio-scsi + scsi-mq <-> > vhost-scsi + per-cpu-ida for quite a bit for benchmarking purposes. Thanks for the clarification, Nicholas. > > I tried git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending.git, > > but it does not appear working without (at least) changes below to SCSI lib: > > > > The only scsi-mq LLD conversions so far have been to virtio-scsi + > scsi_debug to nop REQ_TYPE_FS. I see. Do you think the changes I made is a right way to go? I had to make it to avoid a NULL-pointer assignent and make BIO bounce buffers work, but I do not really understand the mixture of old and new code ( neither in fact :) ) > Just so I understand, your patch below is required in order to make what > LLD function with scsi-mq..? ata_piix > > Thanks! > > --nab > > > Thanks! > > > > diff --git a/drivers/scsi/scsi-mq.c b/drivers/scsi/scsi-mq.c > > index ca6ff67..d8cc7a4 100644 > > --- a/drivers/scsi/scsi-mq.c > > +++ b/drivers/scsi/scsi-mq.c > > @@ -155,6 +155,7 @@ void scsi_mq_done(struct scsi_cmnd *sc) > > static struct blk_mq_ops scsi_mq_ops = { > > .queue_rq = scsi_mq_queue_rq, > > .map_queue = blk_mq_map_queue, > > + .timeout = scsi_times_out, > > .alloc_hctx = blk_mq_alloc_single_hw_queue, > > .free_hctx = blk_mq_free_single_hw_queue, > > }; > > diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c > > index 65360db..33aa373 100644 > > --- a/drivers/scsi/scsi_lib.c > > +++ b/drivers/scsi/scsi_lib.c > > @@ -283,7 +283,10 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, > > /* > > * head injection *required* here otherwise quiesce won't work > > */ > > - blk_execute_rq(req->q, NULL, req, 1); > > + if (q->mq_ops) > > + blk_mq_execute_rq(req->q, req); > > + else > > + blk_execute_rq(req->q, NULL, req, 1); > > > > /* > > * Some devices (USB mass-storage in particular) may transfer > > @@ -298,12 +301,8 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, > > *resid = req->resid_len; > > ret = req->errors; > > out: > > - if (q->mq_ops) { > > - printk("scsi_execute(): Calling blk_mq_free_request >>>\n"); > > - blk_mq_free_request(req); > > - } else { > > + if (!q->mq_ops) > > blk_put_request(req); > > - } > > > > return ret; > > } > > > > > > > And personally, can't wait to run it on the laptop! That's right, I > > > alpha test on the laptop. > > > > > > -- > > > Jens Axboe > > > > > > > -- Regards, Alexander Gordeev agordeev@redhat.com