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Re: More oddities with multiple processor groups
- From: L A Walsh <cygwin at tlinx dot org>
- To: cygwin at cygwin dot com
- Date: Fri, 13 Apr 2018 07:12:53 -0700
- Subject: Re: More oddities with multiple processor groups
- References: <87in8xwre7.fsf@Rainer.invalid>
Achim Gratz wrote:
The problem here is that on Linux you don't need to do anything extra to
use any of the advertised logical processors from a single application,
while on Windows you need to first create a thread and set it's affinity
to a different group than where your process was started in, then assign
each new thread an affinity to one of the available groups. If you
don't do that, all threads will be restricted to the original group.
Not exactly true. They are not *restricted* -- it's a *feature*
of the Windows scheduler, in that future procs/threads inherit the
cpu of the parent. Linux's scheduler is more advanced as well as
being replaceable. MS doesn't want you to do that
need to be some option to restrict Cygwin to a single processor group
for some applications to work (correctly).
There is. Start them all on a single cpu & set the cpu
mask. Pretty much the same way you restrict procs on linux --
you can run them with a specific cpu mask, and most programs will
keep running w/that mask.
Unfortunately, AFAIK, I don't think POSIX specifies
a way to set affinities, so I'm not sure how cygwin would do it.
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