From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751496AbeAPPAG (ORCPT + 1 other); Tue, 16 Jan 2018 10:00:06 -0500 Received: from mx2.suse.de ([195.135.220.15]:32861 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751409AbeAPPAE (ORCPT ); Tue, 16 Jan 2018 10:00:04 -0500 Date: Tue, 16 Jan 2018 16:00:02 +0100 From: Johannes Thumshirn To: Keith Busch Cc: Christoph Hellwig , Sagi Grimberg , Linux Kernel Mailinglist , Hannes Reinecke , Linux NVMe Mailinglist Subject: Re: [PATCH v2 0/2] add tracepoints for nvme command submission and completion Message-ID: <20180116150002.77orcgphqcv52dhh@linux-x5ow.site> References: <20180116142821.11693-1-jthumshirn@suse.de> <20180116145554.GB6259@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180116145554.GB6259@localhost.localdomain> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On Tue, Jan 16, 2018 at 07:55:55AM -0700, Keith Busch wrote: > On Tue, Jan 16, 2018 at 03:28:19PM +0100, Johannes Thumshirn wrote: > > Add tracepoints for nvme command submission and completion. The tracepoints > > are modeled after SCSI's trace_scsi_dispatch_cmd_start() and > > trace_scsi_dispatch_cmd_done() tracepoints and fulfil a similar purpose, > > namely a fast way to check which command is going to be queued into the HW or > > Fabric driver and which command is completed again. > > I like this very much, thanks for doing this. I think you could make the > submission trace point tighter for PCI as Hannes was suggesting since > an MMIO write can't fail, but doesn't look as doable for FC and RDMA. That's what I concluded as well and I wanted to have some sort of smallest common divisor when tracing customer problems on nvme. I think I can come up with additional tracepoints in pci/rdma/fc but these can be added later as well and should not hold up this series. Byte, Johannes -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850