netdev - Re: [PATCH 2/2] pkt_sched: fq: fix pacing for small frames

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] [day] [month] [year] [list]

Message-Id: <20131115.210643.1050495716712111997.davem@davemloft.net>
Date:	Fri, 15 Nov 2013 21:06:43 -0500 (EST)
From:	David Miller <davem@...emloft.net>
To:	eric.dumazet@...il.com
Cc:	netdev@...r.kernel.org, maze@...gle.com, willemb@...gle.com,
	ycheng@...gle.com, ncardwell@...gle.com
Subject: Re: [PATCH 2/2] pkt_sched: fq: fix pacing for small frames

From: Eric Dumazet <eric.dumazet@...il.com>
Date: Fri, 15 Nov 2013 08:58:14 -0800

> From: Eric Dumazet <edumazet@...gle.com>
> 
> For performance reasons, sch_fq tried hard to not setup timers for every
> sent packet, using a quantum based heuristic : A delay is setup only if
> the flow exhausted its credit.
> 
> Problem is that application limited flows can refill their credit
> for every queued packet, and they can evade pacing.
> 
> This problem can also be triggered when TCP flows use small MSS values,
> as TSO auto sizing builds packets that are smaller than the default fq
> quantum (3028 bytes) 
> 
> This patch adds a 40 ms delay to guard flow credit refill.
> 
> Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler")
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>

Applied and queued up for -stable.

Thanks.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html