Question about memcpy

[Himanshu Jha]

On Mon, Jul 09, 2018 at 12:16:27PM -0400, valdis.kletnieks at vt.edu wrote:
> On Mon, 09 Jul 2018 19:34:44 +0530, Himanshu Jha said:
> 
> > I think for these benchmarking stuff, to evaluate the cycles and time
> > correctly you should use the __rdtscp(more info at "AMD64 Architecture
> > Programmer???s Manual Volume 3: General-Purpose and System Instructions"
> > Pg 401)
> 
> Just beware that many Intel (and maybe some AMD) chipsets have a non-constant
> TSC frequency.  Check /proc/cpuinfo for 'constant_tsc' before relying on the value.

How about setting "performance" governor[1] for all CPUs ?
Would that work ? I mean no throttle down, but not sure if we have a
constant cpufreq.

Something like the following script:

for CPUFREQ in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor;
	do [ -f $CPUFREQ ] || continue; 
	echo -n performance > $CPUFREQ;
done

[1] https://www.kernel.org/doc/html/v4.14/admin-guide/pm/cpufreq.html#performance

-- 
Himanshu Jha
Undergraduate Student
Department of Electronics & Communication
Guru Tegh Bahadur Institute of Technology