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Subject: Re: [hwloc-users] Bind current thread to a specific cpu
From: Brice Goglin (Brice.Goglin_at_[hidden])
Date: 2011-08-18 06:02:28


Le 18/08/2011 11:48, PULVERAIL Sébastien a écrit :
>
> I use logical ids, so I do this :
>
>
>
> hwloc_obj_t cpu = hwloc_get_obj_by_type(topology,
> HWLOC_OBJ_PU, i);
>
> int err = hwloc_set_cpubind(topology, cpu->cpuset,
> HWLOC_CPUBIND_THREAD);
>
>
>
> Is it correct ?
>

Yes, it looks OK. This case is easy because cpu->cpuset contains a
single bit (because it's a HWLOC_OBJ_PU), so there's no need to singlify
it (which would have required to allocate a temporary copy with dup()
before modifying with singlify).

Brice

> --
>
> Seb
>
>
>
> *De :*hwloc-users-bounces_at_[hidden]
> [mailto:hwloc-users-bounces_at_[hidden]] *De la part de* Brice Goglin
> *Envoyé :* jeudi 18 août 2011 10:25
> *À :* Hardware locality user list
> *Objet :* Re: [hwloc-users] Bind current thread to a specific cpu
>
>
>
> Are you talking about logical ids (the one given by hwloc) or
> physical/OS ids (the one given by the OS and possibly in strange
> order) ? You should avoid using physical ids, but...
>
> If logical, you can hwloc_get_obj_by_type() to get the corresponding
> object, then use its ->cpuset.
>
> If physical, you just need a cpuset that contains the bit
> corresponding to this id. You can use hwloc_bitmap_only(set, <id>) to
> reset a (previously allocated) cpuset to nothing but this id.
>
> Brice
>
>
>
> Le 18/08/2011 10:10, PULVERAIL Sébastien a écrit :
>
> Hi,
>
>
>
> I'm looking for a function that allows to bind the current thread to a
> specific cpu given by its id.
>
>
>
> I found the function hwloc_set_thread_cpubind to bind a thread to a
> cpuset.
>
> I also found the function hwloc_bitmap_singlify to keep only one index
> in the cpuset.
>
> But I didn't found anything to only keep the cpu I need in my cpuset...
>
>
> Is it possible ?
>
>
>
> --
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> Seb
>
>
>
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