Linux-NVME Archive on lore.kernel.org
 help / color / mirror / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Keith Busch <kbusch@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>,
	John Garry <john.garry@huawei.com>,
	axboe@fb.com, sagi@grimberg.me, linux-nvme@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nvme: Fix nvme_setup_command metadata trace event for cdw10
Date: Wed, 6 Jul 2022 18:34:34 +0200	[thread overview]
Message-ID: <20220706163434.GA2222@lst.de> (raw)
In-Reply-To: <YsW3oXcCe6/y6iRb@kbusch-mbp.dhcp.thefacebook.com>

On Wed, Jul 06, 2022 at 10:26:09AM -0600, Keith Busch wrote:
> On Wed, Jul 06, 2022 at 06:18:25PM +0200, Christoph Hellwig wrote:
> > On Wed, Jul 06, 2022 at 10:13:22AM -0600, Keith Busch wrote:
> > > Did you test what the trace looks like afte this? We're losing valuable trace
> > > data here. The field is supposed to get CDW's 10 - 15, so that's 24 bytes. I
> > > don't know why it cares that the address of the field being read is only 4
> > > bytes; we want everything that comes after it too.
> > 
> > Because accesses should not spawn boundaries of members in structs unless
> > copying the entire struct.  If we want to trace the various fields we
> > need to individually assign them.
> > 
> > Anyway, I'm dropping this patch from nvme-5.19 for now to let the
> > discussion conclude.
> 
> How about this instead?

Maybe a better option would be to use struct_group().


  reply	other threads:[~2022-07-06 16:34 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-06  8:16 [PATCH] nvme: Fix nvme_setup_command metadata trace event for cdw10 John Garry
2022-07-06 16:10 ` Christoph Hellwig
2022-07-06 16:13 ` Keith Busch
2022-07-06 16:18   ` Christoph Hellwig
2022-07-06 16:26     ` Keith Busch
2022-07-06 16:34       ` Christoph Hellwig [this message]
2022-07-06 16:44         ` Keith Busch
2022-07-06 16:58           ` John Garry

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20220706163434.GA2222@lst.de \
    --to=hch@lst.de \
    --cc=axboe@fb.com \
    --cc=john.garry@huawei.com \
    --cc=kbusch@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nvme@lists.infradead.org \
    --cc=sagi@grimberg.me \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox