Open MPI logo

Hardware Locality Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Hardware Locality Development mailing list

Subject: Re: [hwloc-devel] CPUBIND flags when getting proc/thread affinity
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2011-09-20 08:57:11

Le 20/09/2011 14:44, Jeff Squyres a écrit :
> 1. Is it permissible to use _PROCESS or _THREAD with get_proc_last_cpu_location() and get_proc_cpubind()? I'm thinking that it doesn't make sense to use _THREAD here, and using _PROCESS would be redundant.

That's almost true. Except that Linux has this notion of "tid" to
identify single threads. So if you pass THREAD with a thread id, you end
up doing get_cpubind/get_last_location on the corresponding single
thread (without having to use a pthread_t).

This is Linux-specific corner case, sometimes useful, but maybe not
required in the doc?

> 2. Is it permissible to use _PROCESS or _THREAD with get_last_cpu_location() and get_cpubind()?

It's OK.

> 3. Is it permissible to use _NOMEMBIND with any of these 4 functions? I'm guessing that it's meaningless. Should we document that this flag will be ignored, or that it is erroneous to use?

This flag is meaningless and ignored there.