[PATCH] Cygwin: Carry process affinity through to result

[Corinna Vinschen]

On Mar 16 13:55, Mark Geisert wrote:
> On 3/16/2025 7:09 AM, Christian Franke wrote:
> > Mark Geisert wrote:
> [...]
> > 
> > Could only test the single cpu group (aka single physical cpu) case
> > which is the most common, I guess. Works as expected:
> > 
> > $ uname -r
> > 3.6.0-dev-440-g5ec497dc80bc-dirty.x86_64
> > 
> > $ grep '^model name' /proc/cpuinfo | uniq -c
> >       28 model name      : Intel(R) Core(TM) i7-14700K
> > 
> > $ stress-ng --pthread 1 -v &
> > [1] 1323
> > ...
> > stress-ng: debug: [1324] pthread: [1324] started (instance 0 on CPU 10)
> > 
> > $ taskset -c -p 1324
> > pid 1324's current affinity list: 0-27
> > 
> > $ taskset -p fff0000 1324 # All E-cores
> > pid 1324's current affinity mask: fffffff
> > pid 1324's new affinity mask: fff0000
> > 
> > $ taskset -p fff5555 1324 # All cores but no HT
> > pid 1324's current affinity mask: fff0000
> > pid 1324's new affinity mask: fff5555
> > 
> > $ taskset -c -p 8,9 1324 # P-core 4 with HT
> > pid 1324's current affinity list: 0,2,4,6,8,10,12,14,16-27
> > pid 1324's new affinity list: 8,9
> > 
> > $ taskset -p 1324
> > pid 1324's current affinity mask: 300
> > 
> > The settings have the desired effect on reported core usage.
> 
> Thanks very much Christian for testing.  I want to make a minor change to
> the patch:
>     if (procmask == 0)
> will be changed to
>     if (groupcount > 1)
> to make it clearer what's going on.  I will also add a few words to both
> code comments and the patch description saying what will happen on systems
> with more than one cpu group.
> 
> It sure would be nice to test on a system with more than 64 h/w threads but
> I don't have that kind of budget ;-).
> 
> So, v2 patch incoming shortly.  Comments from other folks welcome.

Only one: Thanks for looking into this stuff!

I wonder if, after your v2 patch, it's about time to release 3.6.0.


Thanks,
Corinna