Date: Tue, 16 Jan 2018 07:55:55 -0700
From: Keith Busch <keith.busch@intel.com>
To: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
        Linux Kernel Mailinglist <linux-kernel@vger.kernel.org>,
        Hannes Reinecke <hare@suse.de>,
        Linux NVMe Mailinglist <linux-nvme@lists.infradead.org>
Subject: Re: [PATCH v2 0/2] add tracepoints for nvme command submission and
 completion
Message-ID: <20180116145554.GB6259@localhost.localdomain>
References: <20180116142821.11693-1-jthumshirn@suse.de>
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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.