Thanks for the response.
I looked at the code, and there doesn't seem to be a way to turn it off
dynamically or with a bootline option. I have to have the driver
compiled into the kernel (because I'm netbooting with NFS) so I can't
really use a module parameter.
A dynamic field in /proc would be quite nice.
-Corey
Feldman, Scott wrote:
>>I've attached a small program to measure latency of
>>round-trip time on UDP. If I send 85-byte packets between
>>two of my machines, I get 170us round-trip latency. If I
>>send 86-byte packets, I get 1329us latency.
>>This seems quite odd. If I test on the eepro100 driver, I
>>get expected linear increase in round-trip time as the packet
>>size increases, and it never gets close to 1300us.
>>
>>
>
>This sounds like a side-effect of the "CPU Cycle Saver" feature to
>bundle Rx packets per one interrupt. See
>Documentation/networking/e100.txt. I haven't tried your setup, but I
>would guess that you can play around with the BundleSmallFr module
>parameter, or better yet, if you want the lowest latencies, turn off CPU
>Saver (ucode=0).
>
>CPU Saver trades latency for reduced interrupts, resulting in CPU
>savings, hence the name.
>
>Hope this helps.
>
>-scott
>
>
>
>
-
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This archive was generated by hypermail 2b29 : Thu May 15 2003 - 22:00:58 EST