3:46 a.m.
Hi Viresh,
I'm not sure how the simple commit will impact will-it-scale/pwrite2
throughput. Just in case you can see more clues.
git://git.linaro.org/people/vireshk/linux tick/ONESHOT-STOPPED
commit d5a085970b0b88b8c82303d2c45f09c9427fd02a ("clockevents: x86: add support for
ONESHOT_STOPPED mode")
test case: nhm4/will-it-scale/pwrite2
f4f5df6f142f679 d5a085970b0b88b8c82303d2c
--------------- -------------------------
773859 ~ 0% -9.2% 702704 ~ 0% TOTAL will-it-scale.per_thread_ops
Legend:
~XX% - stddev percent
[+-]XX% - change percent
Disclaimer:
Results have been estimated based on internal Intel analysis and are provided
for informational purposes only. Any difference in system hardware or software
design or configuration may affect actual performance.
Thanks,
Fengguang
6:05 a.m.
On 26 June 2014 07:16, Fengguang Wu <fengguang.wu(a)intel.com> wrote:
I'm not sure how the simple commit will impact
will-it-scale/pwrite2
throughput. Just in case you can see more clues.
git://git.linaro.org/people/vireshk/linux tick/ONESHOT-STOPPED
commit d5a085970b0b88b8c82303d2c45f09c9427fd02a ("clockevents: x86: add support for
ONESHOT_STOPPED mode")
test case: nhm4/will-it-scale/pwrite2
What is this test all about ?
6:39 a.m.
On Thu, Jun 26, 2014 at 09:35:11AM +0530, Viresh Kumar wrote:
On 26 June 2014 07:16, Fengguang Wu <fengguang.wu(a)intel.com>
wrote:
> I'm not sure how the simple commit will impact will-it-scale/pwrite2
> throughput. Just in case you can see more clues.
>
> git://git.linaro.org/people/vireshk/linux tick/ONESHOT-STOPPED
> commit d5a085970b0b88b8c82303d2c45f09c9427fd02a ("clockevents: x86: add support
for ONESHOT_STOPPED mode")
>
> test case: nhm4/will-it-scale/pwrite2
What is this test all about ?
It calls the pwrite2() syscall in parallel, on one single tmpfs file.
https://github.com/antonblanchard/will-it-scale.git
Thanks,
Fengguang
1:07 p.m.
On 26 June 2014 07:16, Fengguang Wu <fengguang.wu(a)intel.com> wrote:
Hi Viresh,
I'm not sure how the simple commit will impact will-it-scale/pwrite2
throughput. Just in case you can see more clues.
git://git.linaro.org/people/vireshk/linux tick/ONESHOT-STOPPED
commit d5a085970b0b88b8c82303d2c45f09c9427fd02a ("clockevents: x86: add support for
ONESHOT_STOPPED mode")
test case: nhm4/will-it-scale/pwrite2
f4f5df6f142f679 d5a085970b0b88b8c82303d2c
--------------- -------------------------
773859 ~ 0% -9.2% 702704 ~ 0% TOTAL will-it-scale.per_thread_ops
Legend:
~XX% - stddev percent
[+-]XX% - change percent
Disclaimer:
Results have been estimated based on internal Intel analysis and are provided
for informational purposes only. Any difference in system hardware or software
design or configuration may affect actual performance.
Hi Fengguang,
Thanks for your link: https://github.com/antonblanchard/will-it-scale.git
You saw these changes because the simple commit you were talking about
changes behavior of code.
To be specific, we are stopping the clock-event devices now when they
aren't used. i.e. during idle periods or in full dynticks.
I still fail to understand why performance came down by 9.2%..
Adding Frederic in CC, in case he can throw some light. But he is currently
on vacations and I don't expect him to reply immediately :)
11:11 p.m.
On 06/25/2014 06:46 PM, Fengguang Wu wrote:
f4f5df6f142f679 d5a085970b0b88b8c82303d2c
--------------- -------------------------
773859 ~ 0% -9.2% 702704 ~ 0% TOTAL will-it-scale.per_thread_ops
Has this impacted more than a single system? I wonder if that system
was using the HPET where all the others were using the TSC.
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4 comments
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Dave Hansen -
Fengguang Wu -
Viresh Kumar