netdev - Re: [PATCH v2 net-next 3/3] net: Use backlog-NAPI to clean up the defer

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240223180257.5d828020@kernel.org>
Date: Fri, 23 Feb 2024 18:02:57 -0800
From: Jakub Kicinski <kuba@...nel.org>
To: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
Cc: netdev@...r.kernel.org, "David S. Miller" <davem@...emloft.net>, Eric
 Dumazet <edumazet@...gle.com>, Jesper Dangaard Brouer <hawk@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Thomas Gleixner <tglx@...utronix.de>,
 Wander Lairson Costa <wander@...hat.com>, Yan Zhai <yan@...udflare.com>
Subject: Re: [PATCH v2 net-next 3/3] net: Use backlog-NAPI to clean up the
 defer_list.

On Wed, 21 Feb 2024 18:00:13 +0100 Sebastian Andrzej Siewior wrote:
> +	if (use_backlog_threads()) {
> +		rps_lock_irqsave(sd, &flags);
> +
> +		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state))
> +			napi_schedule_rps(sd);

Why are you calling napi_schedule_rps() here?
Just do __napi_schedule_irqoff(&sd->backlog);
Then you can move the special case inside napi_schedule_rps()
into the if (sd != mysd) block.

> +		rps_unlock_irq_restore(sd, &flags);

Also not sure if the lock helpers should still be called RPS since they
also protect state on non-RPS configs now.