Re: cpufreq affects traffic control rates

From: Jan Engelhardt
Date: Wed Aug 29 2007 - 11:26:40 EST



On Aug 28 2007 15:23, Stephen Hemminger wrote:
>> I noticed lately that my traffic control rates were being very slow,
>> about 40% less than expected, and finally spotted the problem: cpufreq.
>>
>> Looks like HTB puts buckets according to the requested rate but
>> assuming that the CPU is running at its default clock or something like
>> that.
>>
>Is the problem configuration of network scheduler clock? In 2.6.20 and earlier, you
>could use CPU cycle counter (later kernels only use time of day). So try
>switching to jiffies or gettimeofday.

This should not have been removed. CPUs with constant_tsc
could still be used with "CPU cycle counter" method.


Jan
--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/