From: himanshujha199640@gmail.com (Himanshu Jha)
To: kernelnewbies@lists.kernelnewbies.org
Subject: Question about memcpy
Date: Sat, 14 Jul 2018 15:40:26 +0530 [thread overview]
Message-ID: <20180714101026.GA11804@himanshu-Vostro-3559> (raw)
In-Reply-To: <11030.1531152987@turing-police.cc.vt.edu>
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
next prev parent reply other threads:[~2018-07-14 10:10 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-07 11:36 Question about memcpy bing zhu
2018-07-07 18:44 ` valdis.kletnieks at vt.edu
2018-07-08 14:03 ` bing zhu
2018-07-09 7:54 ` 袁建鹏
2018-07-09 8:14 ` bing zhu
2018-07-09 14:04 ` Himanshu Jha
2018-07-09 16:16 ` valdis.kletnieks at vt.edu
2018-07-14 10:10 ` Himanshu Jha [this message]
2018-07-10 4:50 ` bing zhu
2018-07-10 6:22 ` Greg KH
2018-07-10 14:51 ` bing zhu
2018-07-10 14:57 ` Greg KH
2018-07-10 16:03 ` valdis.kletnieks at vt.edu
2018-07-12 4:47 ` bing zhu
2018-07-12 5:34 ` Greg KH
2018-07-12 14:27 ` bing zhu
2018-07-12 14:53 ` Greg KH
2018-07-13 3:02 ` bing zhu
2018-07-13 7:33 ` valdis.kletnieks at vt.edu
2018-07-17 2:44 ` bing zhu
2018-07-12 16:49 ` valdis.kletnieks at vt.edu
-- strict thread matches above, loose matches on Subject: below --
2018-07-07 13:21 Alex Arvelaez
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