From: David Miller <davem@davemloft.net>
To: peter.p.waskiewicz.jr@intel.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH] PATCH 1/2 [SCHED 2.6.24]: Check subqueue status before calling hard_start_xmit
Date: Tue, 13 Nov 2007 20:41:14 -0800 (PST) [thread overview]
Message-ID: <20071113.204114.28838694.davem@davemloft.net> (raw)
In-Reply-To: <20071113174450.27916.80538.stgit@localhost.localdomain>
From: PJ Waskiewicz <peter.p.waskiewicz.jr@intel.com>
Date: Tue, 13 Nov 2007 09:44:50 -0800
> The only qdiscs that check subqueue state before dequeue'ing are PRIO
> and RR. The other qdiscs, including the default pfifo_fast qdisc, will
> allow traffic bound for subqueue 0 through to hard_start_xmit. The check
> for netif_queue_stopped() is done above in pkt_sched.h, so it is
> unnecessary for qdisc_restart(). However, if the underlying driver is
> multiqueue capable, and only sets queue states on subqueues, this will
> allow packets to enter the driver when it's currently unable to process
> packets, resulting in expensive requeues and driver entries. This patch
> re-adds the check for the subqueue status before calling hard_start_xmit,
> so we can try and avoid the driver entry when the queues are stopped.
>
> Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Applied, and I'll queue up the other one for -stable, thanks.
next prev parent reply other threads:[~2007-11-14 4:41 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-13 17:44 [PATCH] SCHED: Fix unnecesary driver entries when queue is stopped PJ Waskiewicz
2007-11-13 17:44 ` [PATCH] PATCH 1/2 [SCHED 2.6.24]: Check subqueue status before calling hard_start_xmit PJ Waskiewicz
2007-11-14 4:41 ` David Miller [this message]
-- strict thread matches above, loose matches on Subject: below --
2007-11-14 6:04 Krishna Kumar
2007-11-14 6:14 ` David Miller
2007-11-14 7:47 ` Krishna Kumar2
2007-11-14 8:28 ` Krishna Kumar2
2007-11-15 20:57 ` Waskiewicz Jr, Peter P
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