Re: 2.6.9 RCU breakage in dev_queue_xmit

From: Jeff V. Merkey
Date: Wed Nov 10 2004 - 18:36:55 EST

Herbert Xu wrote:

Jeff V. Merkey <jmerkey@xxxxxxxxx> wrote:

Running dual gigabit interfaces at 196 MB/S (megabytes/second) on receive, 12 CLK interacket gap time, 1500 bytes payload
at 65000 packets per second per gigabit interface, and retransmitting received packets at 130 MB/S out of a third gigabit interface
with skb, RCU locks in dev_queue_xmit breaks and enters the following state:

This patch might help.


Even with this patch I still see RCU breakage at these data rates and the problem persists -- it just takes
longer for it to manifest (about 23 hours). I am recoding dev_queue_xmit since the use of RCU primitives
is severely busted. I looked over the code and the fact it breaks on uniprocessor is really a joke. No offense guys, but this is pretty bad. How about something simple, like a spinlock or
multiple send queues per proc?


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