Setting default priority for matlabpool processes

I ran my program, which has a resource heavy function call in a parfor loop, and I noticed my system started to hang frequently. I went into task manager and turned down the priority of every matlab process to alleviate the issue. I was wondering if there was a way to set the default process priority to a different (in my case lower) value. I would still like to do work while my code is running, since it will be going for at least a few hours, and if I need to run it again later, I don't want to have to set them one-by-one in taskman every time.

Answer 1

[Matt Bigelow]

I know this thread is old, but putting the following in a poolStartup.m script (see poolStartup - the file can also be on the MATLAB path) might be a convenient way to solve this:

if ispc
    [~,~] = system(['wmic process where processid=' ...
        num2str(feature('getpid')) ' call setpriority "below normal"']);
end

Using the getpid feature instead of putting in a process name ensures just your workers get a priority change and not your user session and not anyone else's MATLAB sessions or workers (if you're on a machine with multiple users and you have permission to change their process priorities).

Answer 2

[Edric Ellis]

I assume you're running on windows - you could try using this file exchange submission: http://www.mathworks.com/matlabcentral/fileexchange/1841 and call it within an SPMD block.

[Matthew Cordaro]

That would be useful if I felt like compiling every time. Maybe they should consider this for a future version. Thanks for the tip.

Answer 3

[JonasBGood]

I stumbled upon this problem as well. For me (using win7) the system command wmic helps:

matlabpool open
cmd_str = 'wmic process where name="MATLAB.exe" CALL setpriority 64';
[~,~] = system(cmd_str);

This reduces the priority af ALL matlab instances on your local machine to 'low'. The number defines the priority:

idle: 64, below normal: 16384, normal: 32, above normal: 32768, high priority: 128, real time: 256