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Subject: Re: [hwloc-users] OpenGL GPU detection code
From: Kenneth Lloyd (kenneth.lloyd_at_[hidden])
Date: 2013-02-12 23:50:07


I've compiled and run hwloc 1.6.1 on my development machine (Scientific
Linux 6.2) currently with 1) GTX-480 and everything seems to be working

[kalloyd_at_devhost ~]$ lstopo -v
Bridge Host->PCI L#0 (P#0 buses=0000:[00-08])
    Bridge PCI->PCI (P#48 busid=0000:00:03.0 id=8086:340a
class=0604(PCI_B) buses=0000:[02-02] PCIVendor="Intel Corporation"
PCIDevice="5520/5500/X58 I/O Hub PCI Express Root Port 3") "Intel
Corporation 5520/5500/X58 I/O Hub PCI Express Root Port 3"
      PCI 10de:06c0 (P#8192 busid=0000:02:00.0 class=0300(VGA)
PCIVendor="nVidia Corporation" PCIDevice="GF100 [GeForce GTX 480]")
"nVidia Corporation GF100 [GeForce GTX 480]"

lstopo --whole-io shows much more detail, including both sides of the

I haven't yet written an OpenMPI, OpenGL program to see how it works
across a small cluster, but that will give me something to do in my
spare time ...

Ken Lloyd

On Tue, 2013-02-12 at 23:37 +0100, Brice Goglin wrote:

> Stefan (or anybody else interested in hwloc GPU support),
> Did you have any chance to look at this?
> Brice
> Le 01/02/2013 14:57, Brice Goglin a écrit :
> > I just committed big changes to the display branch (and I also merged
> > latest trunk changes).
> >
> > lstopo will now report things like this:
> > PCI 10de:06d1
> > GPU L#0 ":0.0"
> > GPU L#1 "cuda0"
> > GPU L#2 "nvml0"
> >
> >
> > The changes include:
> >
> > 1) We don't have a "display" specific OS device anymore, it's just
> > another kind of GPU among cuda, opencl and nvml. The name is the X
> > server display name. There are string attributes in these new GL GPU OS
> > devices (lstopo -v):
> > GPU L#9 (Backend=GL GPUVendor="NVIDIA Corporation" GPUModel="Tesla
> > C2050") ":0.2"
> >
> > 2) The gl component is now buildable as a plugin
> >
> > 3) Given (2), we can't expose internal GL routines in the public API. So
> > hwloc/gl.h is just made of inline helpers as any other hwloc/foo.h. It
> > now contains functions to convert between displays (name or port/device)
> > and hwloc OS devices:
> >
> > hwloc_obj_t hwloc_gl_get_display_osdev_by_port_device(hwloc_topology_t
> > topology, unsigned port, unsigned device)
> > hwloc_obj_t hwloc_gl_get_display_osdev_by_name(hwloc_topology_t
> > topology, const char *name)
> > int hwloc_gl_get_display_by_osdev(hwloc_topology_t topology, hwloc_obj_t
> > osdev,unsigned *port, unsigned *device)
> >
> > If you really need the PCI device, just use osdev->parent as documented.
> > If you need the locality, use hwloc_get_non_io_ancestor(topology,
> > osdev)->cpuset
> > See tests/gl.c for examples.
> >
> > Please review hwloc/gl.h and let me know if that works for you. I hope I
> > used the words port/device/server/screen as expected.
> >
> > The last thing on my TODO list is to decide is whether we keep the "GL"
> > name or switch to something among display/X11/X/... for filenames and
> > function names.
> >
> > Brice
> >
> _______________________________________________
> hwloc-users mailing list
> hwloc-users_at_[hidden]

Kenneth A. Lloyd, Jr.
CEO - Director of Systems Science
Watt Systems Technologies Inc.
Albuquerque, NM US

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