2008-08-27 14:22:16

by Joe Korty

[permalink] [raw]
Subject: [ETH] forcdeth: increase max_interrupt_work

Forcedeth: increase max_interrupt_work

This eliminates the following often-generated warning from
my 64 bit Opteron SMP test stand:

eth0: too many iterations (6) in nv_nic_irq

According to the web, the problem is that the forcedeth
driver has a too-low value for max_interrupt_work.
Grepping the kernel I see that forcedeth has the second
lowest value of all ethernet drivers (ie, 6). Most are
in the 20-40 range. So this patch increases this a bit,
from 6 to 15 (at 15 forcedeth becomes the driver with
third-lowest max_interrupt_work value).

My test stand, which used to print out the above warnings
repetitively whenever it was under heavy net load, no
longer does so.

Signed-off-by: Joe Korty <[email protected]>

Index: 2.6.27-rc4-git4/drivers/net/forcedeth.c
===================================================================
--- 2.6.27-rc4-git4.orig/drivers/net/forcedeth.c 2008-08-27 09:49:13.000000000 -0400
+++ 2.6.27-rc4-git4/drivers/net/forcedeth.c 2008-08-27 10:02:40.000000000 -0400
@@ -818,7 +818,7 @@
* Maximum number of loops until we assume that a bit in the irq mask
* is stuck. Overridable with module param.
*/
-static int max_interrupt_work = 5;
+static int max_interrupt_work = 15;

/*
* Optimization can be either throuput mode or cpu mode


2008-08-31 10:53:30

by Tobias Diedrich

[permalink] [raw]
Subject: Re: [ETH] forcdeth: increase max_interrupt_work

Joe Korty wrote:
> Forcedeth: increase max_interrupt_work
>
> This eliminates the following often-generated warning from
> my 64 bit Opteron SMP test stand:
>
> eth0: too many iterations (6) in nv_nic_irq
>
> According to the web, the problem is that the forcedeth
> driver has a too-low value for max_interrupt_work.
> Grepping the kernel I see that forcedeth has the second
> lowest value of all ethernet drivers (ie, 6). Most are
> in the 20-40 range. So this patch increases this a bit,
> from 6 to 15 (at 15 forcedeth becomes the driver with
> third-lowest max_interrupt_work value).

I'll add that I also see this warning now and then.

--
Tobias PGP: http://9ac7e0bc.uguu.de
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