Re: [x86/signal] 3aac3ebea0: will-it-scale.per_thread_ops -11.9% regression

[Bae, Chang Seok]

On Dec 7, 2021, at 05:38, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> On Tue, Dec 07 2021 at 09:21, kernel test robot wrote:
>> (please be noted we made some further analysis before reporting out,
>> and thought it's likely the regression is related with the extra spinlock
>> introducded by enalbling DYNAMIC_SIGFRAME. below is the full report.)
>> 
>> FYI, we noticed a -11.9% regression of will-it-scale.per_thread_ops due to commit:
> 
> Does that use sigaltstack() ?

FWIW, I was also wondering about this with:

$ git clone https://github.com/antonblanchard/will-it-scale.git
$ cd will-it-scale/
$ git grep sigaltstack
$

But, the test seems to use python via runtest.py. And the python code has
sigaltstack():
    https://github.com/python/cpython/blob/main/Modules/faulthandler.c#L454

Thanks,
Chang