netdev - Re: [PATCH net-next v3 4/7] net: provide macros for commonly copied lockless queue stop/wake code

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: <ZC5zK2lLSF31VUm9@gondor.apana.org.au>
Date:   Thu, 6 Apr 2023 15:22:19 +0800
From:   Herbert Xu <herbert@...dor.apana.org.au>
To:     Jakub Kicinski <kuba@...nel.org>
Cc:     davem@...emloft.net, netdev@...r.kernel.org, edumazet@...gle.com,
        pabeni@...hat.com, alexander.duyck@...il.com, hkallweit1@...il.com,
        andrew@...n.ch, willemb@...gle.com
Subject: Re: [PATCH net-next v3 4/7] net: provide macros for commonly copied
 lockless queue stop/wake code

On Wed, Apr 05, 2023 at 03:31:31PM -0700, Jakub Kicinski wrote:
>
> +/**
> + * __netif_txq_maybe_wake() - locklessly wake a Tx queue, if needed
> + * @txq:	struct netdev_queue to stop/start
> + * @get_desc:	get current number of free descriptors (see requirements below!)
> + * @start_thrs:	minimal number of descriptors to re-enable the queue
> + * @down_cond:	down condition, predicate indicating that the queue should
> + *		not be woken up even if descriptors are available
> + *
> + * All arguments may be evaluated multiple times.
> + * @get_desc must be a formula or a function call, it must always
> + * return up-to-date information when evaluated!
> + *
> + * Returns:
> + *	 0 if the queue was woken up
> + *	 1 if the queue was already enabled (or disabled but @down_cond is true)
> + *	-1 if the queue was left stopped

Perhaps we should say left unchanged instead of left stopped.
Just in case someone tries to be pedantic ten years later and
then claims the code to be buggy :)

Otherwise

Acked-by: Herbert Xu <herbert@...dor.apana.org.au>

Thanks,
-- 
Email: Herbert Xu <herbert@...dor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt