From: Stephen Hemminger <shemminger@vyatta.com>
To: Daniel Walker <dwalker@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>,
Jim Harford <c_jharfo@quicinc.com>,
netdev@vger.kernel.org
Subject: Re: [PATCH] net: Fix race condition on receive path.
Date: Fri, 5 Mar 2010 13:21:18 -0800 [thread overview]
Message-ID: <20100305132118.1855617a@nehalam> (raw)
In-Reply-To: <1267817699.30393.8.camel@c-dwalke-linux.qualcomm.com>
On Fri, 05 Mar 2010 11:34:59 -0800
Daniel Walker <dwalker@codeaurora.org> wrote:
> Fixes a race condition on the networking receive path that causes all
> received packets to be dropped after 15-60 minutes of heavy network usage.
> Function process_backlog() empties the receive queue, re-enables
> interrupts, then "completes" the softIRQ. This provides a time window for
> netif_rx() to execute (in IRQ context) and enqueue a received packet
> without re-scheduling the softIRQ. After this, the receive queue is never
> processed and the system eventually begins to drop all received packets.
I wonder why this hasn't shown up before?
Where exactly is the window between empty process_backlog and netif_rx?
Maybe it is ARM specific behavior of softirq?
next prev parent reply other threads:[~2010-03-05 21:21 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-05 19:34 [PATCH] net: Fix race condition on receive path Daniel Walker
2010-03-05 21:21 ` Stephen Hemminger [this message]
2010-03-05 23:41 ` Harford, Jim
2010-03-05 23:44 ` Daniel Walker
2010-03-05 23:48 ` Stephen Hemminger
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