[PD] Subprocess CPU core check

[Charles Z Henry]

Hi Popesz,

Are you using [ggee/shell] ?

Here's an example that works on my linux machine

[taskset -c 2 $_ -noaudio >/dev/null & P=$! && echo $P  && wait $P(
|
[ggee/shell]
|
[f ]    ///the PID

When I run that command, $_ is a bash variable (see [env( - [shell] -
[print] for full environment) that has the full path to the pd binary
in use.  You may have to replace "$_" with something more appropriate
to your system
I added -noaudio, because my first pd process is handling audio I/O.
I don't need stdout from pd itself, so I added ">/dev/null".  The
process shows up in top or htop with those arguments included.  You
could distinguish between your processes by some environment variable
or set of options to pd in the command.
"& P=$! " launches pd into the background and records a variable P for
its PID.  There may be other ways of doing this.
"&& echo $P && wait $P"  causes the shell started by [shell] to output
the PID to stdout (the left outlet).  Without "wait $P", [shell]
outputs a bang from its right outlet immediately.  Using "wait $P"
allows [shell] to maintain the status of the process, and it outputs a
bang when the process ends.

Using htop, I see that the process starts and runs on CPU "3".
Taskset must use a CPU numbering that starts at 0, and htop counts
CPU's from 1.

Chuck



On Fri, Mar 20, 2020 at 10:23 AM Csaba Láng <langcsaba at gmail.com> wrote:
>
> Dear list,
> I am getting closer to the solution of binding process to a certain core with taskset.
> e.g. taskset 0xa gedit will bind the gedit to the tenth core.
>
> Now the problem is that I cannot identify the subprocess by its name as it will be pd too, and the PID will be always different so cannot use that number too.
> What would be the logical solution for starting the subprocess from pd with the taskedit command?
>
> Thanks in advance for any help,
>
> Popesz
>
> On Thu, Mar 5, 2020 at 11:14 PM IOhannes m zmölnig <zmoelnig at iem.at> wrote:
>>
>> On 3/5/20 10:48 PM, Charles Z Henry wrote:
>> > On Thu, Mar 5, 2020 at 4:14 AM Max <abonnements at revolwear.com> wrote:
>> >>
>> >> A glance at the System Monitor CPU history graph should give you an idea.
>> >>
>>
>> i usually use 'htop', which is a much improved version of top which also
>> (among verious other interesting things) gives you the CPU of a process.
>>
>> >
>> > Second, you can bind processes to certain CPUs.  This is called "CPU
>> > affinity" and it's controlled by the linux command "taskset".  This
>> > looks like a fine explanation
>>
>>
>> but keep in mind that the people who designed the muticore scheduling
>> algorithms most likely will have a better idea of how to ideally
>> distribute multiple processes onto multiple CPUs.
>>
>> gmsdr
>> IOhannes
>>
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