Why is taskset still not in util-linux?

[Brian Inglis]

On 2020-03-23 03:42, Mark Geisert wrote:
> Corinna Vinschen wrote:
>> On Mar 21 10:41, Brian Inglis wrote:
>>> On 2020-03-21 02:18, Mark Geisert wrote:
>>>> Eliot Moss wrote:
>>>>> On 3/20/2020 1:54 AM, Mark Geisert wrote:
>>>>>> I've reproduced your snags. It/they are due to my having forgotten
>>>>>> another tiny update that should have been part of the
>>>>>> 2.33.1-cygwin-cpuset.patch file.  If you
>>>>>> 'echo "#define SYS_sched_getaffinity 42" > /usr/local/include/sys/syscall.h'
>>>>>> and then back out your other fix attempts, the build using cygport should
>>>>>> work.
>>>>> Once I did that properly, it built without commenting out that test. Yay!
>>>
>>>> I ended up installing Process Lasso to follow processes among the cpus and to
>>>> test the Cygwin affinity mask implementation.  It has a free trial period.  And
>>>> I wrote a simple test program that just advances from one cpu to the next
>>>> repeatedly, cpu-bound between steps, so PL can display the changing cpu.
>>>
>>> Anyone know if this feature support or what feature support will get top P/last
>>> used CPU and/or procps-ng P/sgi_p currently executing CPU and PSR/currently
>>> assigned CPU showing actual CPUs rather than 0/zero?
>>>
>>> Anyone know if or where or how this info is available on Windows or a link to
>>> it? I've looked at Google and SO results and nothing useful is apparent.
>>
>> Can't we just fake the calls?

The results are currently faked to CPU # 0.

> Brian is asking for a way to watch processes globally, as they are scheduled
> back and forth on the available cpus.  I was a bit sloppy in my wording above;
> what Process Lasso displays is the changing process affinity mask for a process
> I wrote to do just that.  I don't know of a way to ask Windows which cpu a
> process is currently scheduled onto.

You can also get and set affinity in Task Manager, and also ideal CPU info using
SysInternals Process Explorer, or PowerShell, which I use to launch Windows ntpd
at max realtime priority on CPU `nproc` - 1, as CMD arithmetic was nonexistent
or obscure years ago. I could probably redo that with CMD start.

Only documented CPU # call I could find was GetCurrentProcessorNumber (-Ex also
returns processor group) which tells the current thread where it's executing,
not the last or current CPU # assigned or used for other process threads.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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