public inbox for netdev@vger.kernel.org
 help / color / mirror / Atom feed
From: Paolo Abeni <pabeni@redhat.com>
To: Qingfang Deng <dqfext@gmail.com>,
	Andrew Lunn <andrew+netdev@lunn.ch>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>,
	linux-ppp@vger.kernel.org, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org
Cc: Paul Mackerras <paulus@ozlabs.org>
Subject: Re: [PATCH net-next 2/2] ppp: remove pch->chan NULL checks from tx path
Date: Tue, 17 Mar 2026 10:57:38 +0100	[thread overview]
Message-ID: <7b082017-5245-434c-9668-49b630af6484@redhat.com> (raw)
In-Reply-To: <20260312093732.277254-2-dqfext@gmail.com>

On 3/12/26 10:37 AM, Qingfang Deng wrote:
> Now that ppp_disconnect_channel() is called before pch->chan is set to
> NULL, a channel from ppp->channels list on the transmit path is
> guaranteed to have non-NULL pch->chan.
> 
> Remove the pch->chan NULL checks from ppp_push(), ppp_mp_explode(), and
> ppp_fill_forward_path(), where a channel is obtained from the list.
> Remove the corresponding WRITE/READ_ONCE annotations as they no longer
> race.
> 
> Signed-off-by: Qingfang Deng <dqfext@gmail.com>

Looks sane to me.

It looks like you are investing a significant amount of effort to
improve the ppp driver. I strongly suggest you to create some functional
self-tests before any other changes in this area.

The code is pretty intricate and obscure, a reasonable code coverage
could add significant confidence in non trivial changes, and could
possibly help revisiting/cleaning-up the locking schema (which is AFAICS
the most significant pain-point).

/P


  reply	other threads:[~2026-03-17  9:57 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-12  9:37 [PATCH net-next 1/2] ppp: disconnect channel before nullifying pch->chan Qingfang Deng
2026-03-12  9:37 ` [PATCH net-next 2/2] ppp: remove pch->chan NULL checks from tx path Qingfang Deng
2026-03-17  9:57   ` Paolo Abeni [this message]
2026-03-17 10:10 ` [PATCH net-next 1/2] ppp: disconnect channel before nullifying pch->chan patchwork-bot+netdevbpf

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=7b082017-5245-434c-9668-49b630af6484@redhat.com \
    --to=pabeni@redhat.com \
    --cc=andrew+netdev@lunn.ch \
    --cc=davem@davemloft.net \
    --cc=dqfext@gmail.com \
    --cc=edumazet@google.com \
    --cc=kuba@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-ppp@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=paulus@ozlabs.org \
    /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