From: Joe Damato <joe@dama•to>
To: Martin Karsten <mkarsten@uwaterloo•ca>
Cc: "David S. Miller" <davem@davemloft•net>,
"Eric Dumazet" <edumazet@google•com>,
"Jakub Kicinski" <kuba@kernel•org>,
"Paolo Abeni" <pabeni@redhat•com>,
"Simon Horman" <horms@kernel•org>,
"Tariq Toukan" <tariqt@nvidia•com>,
"Gal Pressman" <gal@nvidia•com>, "Bj�rn T�pel" <bjorn@kernel•org>,
"Frederik Deweerdt" <fdeweerdt@fastly•com>,
"Dragos Tatulea" <dtatulea@nvidia•com>,
netdev@vger•kernel.org, linux-kernel@vger•kernel.org
Subject: Re: [PATCH net-next v3] net: napi: Skip last poll when arming gro timer in busy poll
Date: Mon, 18 May 2026 15:45:25 -0700 [thread overview]
Message-ID: <aguWhSb6/PBKqJC+@devvm20253.cco0.facebook.com> (raw)
In-Reply-To: <20260518181337.886459-1-mkarsten@uwaterloo.ca>
On Mon, May 18, 2026 at 02:13:32PM -0400, Martin Karsten wrote:
> Skip the extra call to napi->poll(), if the gro timer is armed at the
> end of busy polling. This removes the need for having a separate
> __busy_poll_stop() routine and its code is moved directly into the
> relevant places in busy_poll_stop(). Remove obsolete comment about
> ndo_busy_poll_stop().
>
> This is a follow-up to commit 58e2330bd455 ("net: napi: Avoid gro timer
> misfiring at end of busypoll"), which has deferred arming the gro timer
> to the end of __busy_poll_stop() to eliminate a race condition between
> a short timer and long poll that could leave the queue stuck with
> interrupts disabled and no timer armed.
>
> Co-developed-by: Dragos Tatulea <dtatulea@nvidia•com>
> Signed-off-by: Dragos Tatulea <dtatulea@nvidia•com>
> Signed-off-by: Martin Karsten <mkarsten@uwaterloo•ca>
> ---
> Changes since v2 [1]:
> - Fix patch formatting problems.
> - Leave STATE_PREFER_BUSY_POLL bit set when timer is armed.
> Don't want interrupts anyway until timer clears STATE_PREFER_BUSY_POLL.
>
> Changes since RFC [2]:
> - Sending only the cleanup/improvement patch to net-next.
> - Expand commit message to summarize original issue.
> - Streamline control flow.
> - Improve comments.
>
> [1] https://lore.kernel.org/all/f0ecdde3-de16-47ba-b795-fe0042114e96@uwaterloo.c/
> [2] https://lore.kernel.org/all/20260428175134.1197036-4-dtatulea@nvidia.com/
> ---
> net/core/dev.c | 63 ++++++++++++++++++++++----------------------------
> 1 file changed, 28 insertions(+), 35 deletions(-)
Reviewed-by: Joe Damato <joe@dama•to>
next prev parent reply other threads:[~2026-05-18 22:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-18 18:13 [PATCH net-next v3] net: napi: Skip last poll when arming gro timer in busy poll Martin Karsten
2026-05-18 22:45 ` Joe Damato [this message]
2026-05-21 14:13 ` Paolo Abeni
2026-05-21 15:42 ` Martin Karsten
2026-05-21 16:19 ` Paolo Abeni
2026-05-22 23:50 ` Jakub Kicinski
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=aguWhSb6/PBKqJC+@devvm20253.cco0.facebook.com \
--to=joe@dama$(echo .)to \
--cc=bjorn@kernel$(echo .)org \
--cc=davem@davemloft$(echo .)net \
--cc=dtatulea@nvidia$(echo .)com \
--cc=edumazet@google$(echo .)com \
--cc=fdeweerdt@fastly$(echo .)com \
--cc=gal@nvidia$(echo .)com \
--cc=horms@kernel$(echo .)org \
--cc=kuba@kernel$(echo .)org \
--cc=linux-kernel@vger$(echo .)kernel.org \
--cc=mkarsten@uwaterloo$(echo .)ca \
--cc=netdev@vger$(echo .)kernel.org \
--cc=pabeni@redhat$(echo .)com \
--cc=tariqt@nvidia$(echo .)com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
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