Sure!. Great thanks Brice.
On Mon, Sep 26, 2016 at 10:58 PM, Brice Goglin <brice.gog...@inria.fr> wrote: > To be future-proof (so that your code works both with current hwloc 1.x > and upcoming 2.0), the best check for non-NUMA machines is > hwloc_get_nbobjs_by_type(topology, HWLOC_OBJ_NODE) <= 1 > > Otherwise, yes. Infinite/full nodeset means no NUMA. To actually check > whether a nodeset is infinite, use hwloc_bitmap_weight(obj->nodeset). It > returns -1 on infinite/full bitmaps since there's no way to count an > infinite set of bits. > > Brice > > > > Le 27/09/2016 07:45, Swati Agrawal a écrit : > > Thanks Brice for the detailed info. > So, can I say that if obj->nodeset is all 1s, it is a no NUMA mode setup? > > Thanks, > Swati > > On Monday, September 26, 2016, Brice Goglin < <brice.gog...@inria.fr> > brice.gog...@inria.fr> wrote: > >> Hello >> >> If there's no NUMA node object in your hwloc topology, it means your >> machine isn't NUMA (there's a single NUMA node), or your system doesn't >> report NUMA information at all (missing NUMA support in the kernel, etc). >> >> This is an old design choice that is not convenient. So we'll change that >> in the upcoming hwloc 2.0. There will always be at least one NUMA node >> object (just like in lspcu). >> >> In the meantime, the meaning of obj->nodeset isn't very useful when >> there's no NUMA object anyway. If you really need to look at obj->nodeset >> on non-NUMA machines, you'll get either NULL or a "full" "infinite" bitmap >> (meaning "the entire machine memory", as explained in the description of >> the nodeset attribute of the object structure >> https://www.open-mpi.org/projects/hwloc/doc/v1.11.4/a00038. >> php#a08f0d0e16c619a6e653526cbee4ffea3). >> >> By the way, you're not supposed to look at internal nodeset fields >> (ulongs and ulongs_count). For instance, there's another field saying that >> the bitmap is infinite. All these are private details not meant to be >> understood by users. Things like hwloc_bitmap_asprintf() or "lstopo -.xml" >> would show that obj->nodeset is 0xf...f which means "infinite" or "full". >> >> Again, these infinite nodesets will go away in the upcoming hwloc 2.0. >> >> Brice >> >> >> >> >> >> >> Le 27/09/2016 01:35, Swati Agrawal a écrit : >> >> Hi All, >> >> I have recently started using hwloc and stuck with a case where there are >> no NUMA nodes. I see that when i run "lscpu" command, it shows me there is >> 1 Numa Node and all the PUs are in this node. >> But when i try reading the nodeset for my object using >> hwloc_get_non_io_ancestor_obj(..), I see below output: >> >> obj->nodeset->ulongs_count = 1; >> obj->nodeset->ulongs[0] = 18446744073709551615 (UINT64 MAX Value). >> >> What does this actually mean? >> >> Thanks, >> Swati >> >> >> _______________________________________________ >> hwloc-devel mailing >> listhwloc-de...@lists.open-mpi.orghttps://rfd.newmexicoconsortium.org/mailman/listinfo/hwloc-devel >> >> _______________________________________________ > hwloc-devel mailing > listhwloc-de...@lists.open-mpi.orghttps://rfd.newmexicoconsortium.org/mailman/listinfo/hwloc-devel > > > _______________________________________________ > hwloc-devel mailing list > hwloc-devel@lists.open-mpi.org > https://rfd.newmexicoconsortium.org/mailman/listinfo/hwloc-devel >
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