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Subject: Re: [hwloc-devel] [hwloc-svn] svn:hwloc r1333
From: Samuel Thibault (samuel.thibault_at_[hidden])
Date: 2009-11-12 11:44:07


Jeff Squyres, le Thu 12 Nov 2009 08:28:32 -0800, a écrit :
> One thing to not forget is that some (many?) applications don't care a
> whit about portability to other OS's. You view feature X as a
> portability horror; they view it as a feature.
>
> Hence, they may actually *want* to take advantage of the ability to
> pin a specific thread (that is not the current thread).

I'm not saying pinning a specific thread is a horror. I'm saying
expressing which thread should be bound through tids instead of
pthread_t is. The only sane way I could see an application use tids
is a monitoring application that looks into /proc/*/task/* . In that
case, ok we can expose the hwloc_linux_set_tid_cpubind function in a
hwloc/linux.h header, and we need it for complete PLPA support anyway.

What I'm against is even mentioning such thing in the main hwloc.h; tid
vs pid vs pthread_t has been confused enough by Linus before the 2.6 fix
(to the point that I still see parallel programming courses explaining
the 2.4 semantic...)

Samuel