Hi Samuel, yhanks for yout quick reply!
But i have a litte doubt. in a non SMT machine, Is it better use this: hwloc_obj_t core = hwloc_get_obj_by_type(topology, HWLOC_OBJ_CORE, tid); hwloc_cpuset_t set = hwloc_bitmap_dup(core->cpuset); hwloc_bitmap_singlify(set); hwloc_set_cpubind(topology, set, HWLOC_CPUBIND_THREAD); or: hwloc_obj_t core = hwloc_get_obj_by_type(topology, HWLOC_OBJ_PU, tid); hwloc_cpuset_t set = hwloc_bitmap_dup(core->cpuset); hwloc_bitmap_singlify(set); hwloc_set_cpubind(topology, set, HWLOC_CPUBIND_THREAD); because work in the same way( i suppose). 2011/7/29 Samuel Thibault <samuel.thiba...@inria.fr> > Hello, > > Gabriele Fatigati, le Fri 29 Jul 2011 12:43:47 +0200, a écrit : > > I'm so confused. I see couples of cores with the same core id! ( Core#8 > for > > example) How is it possible? > > That's because they are on different sockets. These are physical IDs > (not logical IDs), and are thus not garanteed to be unique. > > > 2) logical Core id and Physical core id maybe differents. If i want to be > sure > > that id 0 and id 1 are physically near, i have to use core id or PU id? > PU ids > > are ever physically near? > > Using core or thread ID does not matter. What matters is that you take > the proper ID. Physical IDs will in general never bring you any > proximity indication. What you want is logical IDs, which hwloc takes > care of meaning proximity. Using adjacent logical IDs (be it for core or > threads) will bring you adjacent cores/threads. > > > 3) Binding a thread on a core, what's the difference > between hwloc_set_cpubind > > () and hwloc_set_thread_cpubind()? More in depth, my code example works > well > > with: > > > > hwloc_set_cpubind(topology, set, HWLOC_CPUBIND_THREAD); > > > > and crash with: > > > > hwloc_set_thread_cpubind(topology, tid, set, HWLOC_CPUBIND_THREAD); > > Note that tid is hwloc_thread_t, i.e. pthread_t on unixes. > It is not a (Linux-specific) tid. If what you have is a (Linux-specific) > tid, use the Linux-specific function, hwloc_linux_set_tid_cpubind. > > Samuel > _______________________________________________ > hwloc-users mailing list > hwloc-us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/hwloc-users > -- Ing. Gabriele Fatigati Parallel programmer CINECA Systems & Tecnologies Department Supercomputing Group Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy www.cineca.it Tel: +39 051 6171722 g.fatigati [AT] cineca.it
