linux-nvme.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
From: Daniel Wagner <dwagner@suse.de>
To: Keith Busch <kbusch@kernel.org>
Cc: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
	 Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
	Hannes Reinecke <hare@suse.de>
Subject: Re: [RFC v1] nvme: add cse, ds, ms, nsze and nuse to sysfs
Date: Mon, 27 Nov 2023 13:07:32 +0100	[thread overview]
Message-ID: <mwen6fl5yszmk5nh2hbsqtu5pu76ir6rh6jpdfppbczsov7qfz@vivqeew6y7wk> (raw)
In-Reply-To: <ZWRy-4Bhqw0Gxo4c@kbusch-mbp.dhcp.thefacebook.com>

On Mon, Nov 27, 2023 at 03:44:11AM -0700, Keith Busch wrote:
> On Mon, Nov 27, 2023 at 11:32:08AM +0100, Daniel Wagner wrote:
> > libnvme is using the sysfs for enumarating the nvme resources. Though
> > there are few missing attritbutes in the sysfs. For these libnvme issues
> > commands during discovering.
> > 
> > As the kernel already knows all these attributes and we would like to
> > avoid libnvme to issue commands all the time, expose these missing
> > attributes.
> 
> The id namespace 'nuse' field can be quite volatile: it can change on
> any write or discard command, so caching it may quickly get out of sync
> with the actual value.

libnvme itself is also cashing this value and exposes it via the
nvme_ns_get_lba_util() getter. I'd say libnvme shouldn't cache it
either. Instead the function should just issue the ns command to report
the current nuse value.

I'll drop the nuse sysfs entry.

Unfortunately, 'nvme list' is using the 'nuse' field for showing the
currently used space. I was hoping to get 'nvme list' working without
issuing any commands.


  reply	other threads:[~2023-11-27 12:05 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-27 10:32 [RFC v1] nvme: add cse, ds, ms, nsze and nuse to sysfs Daniel Wagner
2023-11-27 10:44 ` Keith Busch
2023-11-27 12:07   ` Daniel Wagner [this message]
2023-11-27 13:57     ` Christoph Hellwig
2023-11-27 14:18 ` Christoph Hellwig
2023-11-27 15:44   ` Keith Busch
2023-11-27 15:56     ` Christoph Hellwig
2023-11-27 16:30       ` Keith Busch
2023-11-27 16:33         ` Christoph Hellwig
2023-11-27 16:46           ` Keith Busch
2023-11-28  8:21             ` Daniel Wagner
2023-11-28 10:06               ` Sagi Grimberg
2023-11-28 13:05             ` Christoph Hellwig
2023-11-28 19:02               ` Keith Busch

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=mwen6fl5yszmk5nh2hbsqtu5pu76ir6rh6jpdfppbczsov7qfz@vivqeew6y7wk \
    --to=dwagner@suse.de \
    --cc=hare@suse.de \
    --cc=hch@lst.de \
    --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;
as well as URLs for NNTP newsgroup(s).