From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751149AbeAVP77 (ORCPT ); Mon, 22 Jan 2018 10:59:59 -0500 Received: from verein.lst.de ([213.95.11.211]:53145 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751007AbeAVP76 (ORCPT ); Mon, 22 Jan 2018 10:59:58 -0500 Date: Mon, 22 Jan 2018 16:59:56 +0100 From: Christoph Hellwig To: Johannes Thumshirn Cc: Christoph Hellwig , Sagi Grimberg , Keith Busch , Linux Kernel Mailinglist , Hannes Reinecke , Linux NVMe Mailinglist , "Martin K . Petersen" Subject: Re: [PATCH v4 1/2] nvme: add tracepoint for nvme_setup_cmd Message-ID: <20180122155956.GA6635@lst.de> References: <20180119141819.11938-1-jthumshirn@suse.de> <20180119141819.11938-2-jthumshirn@suse.de> <20180122152301.GA5818@lst.de> <20180122155356.4doy32sfgzwegmq4@linux-x5ow.site> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180122155356.4doy32sfgzwegmq4@linux-x5ow.site> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jan 22, 2018 at 04:53:56PM +0100, Johannes Thumshirn wrote: > Yes and no. I personally like to have the big hammer when tracing customer > problems and filter out maunally later. I initially had a tracepoint for each > of nvme_setup_flush(), nvme_setup_discard(), nvme_setup_rw() but decided it > was too fine grained. > > nvme_setup_cmd() has the nice side effect that all commands, including > userspace passtrough commands must pass it. This was extremely helpful in the > customer bug which inspired me to implement this tracepoint. Not arguing against placing the tracepoint(s) in nvme_setup_cmd, but it seems like we should have one for admin and one for I/O commands. Especially as we have to special case them just about everywhere, and the overlap of the opcode space is pretty annoying.