From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751089AbeAPOTv (ORCPT + 1 other); Tue, 16 Jan 2018 09:19:51 -0500 Received: from mx2.suse.de ([195.135.220.15]:55348 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbeAPOTu (ORCPT ); Tue, 16 Jan 2018 09:19:50 -0500 Date: Tue, 16 Jan 2018 15:19:47 +0100 From: Johannes Thumshirn To: Hannes Reinecke Cc: Christoph Hellwig , Sagi Grimberg , Keith Busch , Linux Kernel Mailinglist , Linux NVMe Mailinglist Subject: Re: [PATCH 1/2] nvme: add tracepoint for nvme_setup_cmd Message-ID: <20180116141947.5fypmthkmb573jkp@linux-x5ow.site> References: <20180116103401.7883-1-jthumshirn@suse.de> <20180116103401.7883-2-jthumshirn@suse.de> <52018c96-854b-95e3-b333-9b8a16782bc7@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <52018c96-854b-95e3-b333-9b8a16782bc7@suse.de> 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 12:27:33PM +0100, Hannes Reinecke wrote: > In general I'd rather have the tracepoints when actually submitting the > request; with this tracepoint we might be getting a trace which doesn't > really indicate if the command was submitted at all. yes but if we really want to be 100% certain we need to take the tracepoints in either in blk_mq_dispatch_rq_list() and trace the return value of the respective ->queue_rq() or in the PCI/FC/RDMA drivers. -- 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