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Subject: Re: [hwloc-devel] How to get information about hwloc objects?
From: Jirka Hladky (jhladky_at_[hidden])
Date: 2010-07-12 18:28:40

Hi Brice,

> I don't like long names like that :) I currently vote for --intersect
> here since this option list the indexes of all objects that intersect
> the input within the given depth or type.
I don't mind long descriptive names. I'm copying options usually from man page
or ./command --help output. Of course, if there is good short name it's the

> --intersect <type|depth>
> Find the list of objects of the given type or depth that
> intersect the CPU set and report the comma-separated list of their
> indexes instead of the cpu mask string. This may be used for determining
> the list of objects above or below the input objects. When combined
> with --physical, the list is convenient to pass to external tools such as
> taskset or numactl --physcpubind or --membind. This is different from
> --largest since the latter requires that all reported objects are strictly
> included inside the input objects.

Cool! :-)

> > 2) I would rename --objects to something like
> > --info_about_nearest_ancestor
> > or perhaps just
> > --ancestor
> I currently vote for --largest (or something about
> summarizing/synthetizing) since this option groups input objects and
> summarizes them into larger ancestors.
> --largest Report the list of largest objects exactly included of the input
> objects. None of these output objects intersect each other, and the
> sum of them is exactly equivalent to the input. No largest object is
> included in the input This is different from --intersect where
> reported objects may not be strictly included in the input.
IMHo, it's also very good name for this option. I would however rephrase help

"Report the list of largest objects which completely include all input objects

It took me a while to understand how user could benefit from such option. Now I
see it:-) Please be sure to include some examples.
Machine (4025MB) cpuset=0x0000ffff
  NUMANode #0 (phys=0 2005MB) cpuset=0x00005555
    Socket #0 cpuset=0x00005555
      L3 #0 (12MB) cpuset=0x00005555
        L2 #0 (256KB) cpuset=0x00000101
          L1 #0 (32KB) cpuset=0x00000101
            Core #0 cpuset=0x00000101
              PU #0 (phys=0) cpuset=0x00000001
              PU #1 (phys=8) cpuset=0x00000100
        L2 #1 (256KB) cpuset=0x00000404
          L1 #1 (32KB) cpuset=0x00000404
            Core #1 cpuset=0x00000404
              PU #2 (phys=2) cpuset=0x00000004
              PU #3 (phys=10) cpuset=0x00000400
        L2 #2 (256KB) cpuset=0x00001010
          L1 #2 (32KB) cpuset=0x00001010
            Core #2 cpuset=0x00001010
              PU #4 (phys=4) cpuset=0x00000010
              PU #5 (phys=12) cpuset=0x00001000
        L2 #3 (256KB) cpuset=0x00004040
          L1 #3 (32KB) cpuset=0x00004040
            Core #3 cpuset=0x00004040
              PU #6 (phys=6) cpuset=0x00000040
              PU #7 (phys=14) cpuset=0x00004000
  NUMANode #1 (phys=1 2020MB) cpuset=0x0000aaaa
    Socket #1 cpuset=0x0000aaaa
      L3 #1 (12MB) cpuset=0x0000aaaa
        L2 #4 (256KB) cpuset=0x00000202
          L1 #4 (32KB) cpuset=0x00000202
            Core #4 cpuset=0x00000202
              PU #8 (phys=1) cpuset=0x00000002
              PU #9 (phys=9) cpuset=0x00000200
        L2 #5 (256KB) cpuset=0x00000808
          L1 #5 (32KB) cpuset=0x00000808
            Core #5 cpuset=0x00000808
              PU #10 (phys=3) cpuset=0x00000008
              PU #11 (phys=11) cpuset=0x00000800
        L2 #6 (256KB) cpuset=0x00002020
          L1 #6 (32KB) cpuset=0x00002020
            Core #6 cpuset=0x00002020
              PU #12 (phys=5) cpuset=0x00000020
              PU #13 (phys=13) cpuset=0x00002000
        L2 #7 (256KB) cpuset=0x00008080
          L1 #7 (32KB) cpuset=0x00008080
            Core #7 cpuset=0x00008080
              PU #14 (phys=7) cpuset=0x00000080
              PU #15 (phys=15) cpuset=0x00008000
[root_at_dell-per810-01 utils]# hwloc-calc proc:0
[root_at_dell-per810-01 utils]# hwloc-calc proc:0-1
[root_at_dell-per810-01 utils]# hwloc-calc --objects proc:0
[root_at_dell-per810-01 utils]# hwloc-calc --objects proc:0-1
[root_at_dell-per810-01 utils]# hwloc-calc --objects proc:0-5
L2Cache:0 L2Cache:1 L2Cache:2
[root_at_dell-per810-01 utils]# hwloc-calc --objects proc:0-7

Another example
[root_at_amd-dinar-02 utils]# hwloc-calc --objects $(hwloc-distrib --single 4)
L2Cache:0 L2Cache:6 L2Cache:12 L2Cache:18
[root_at_amd-dinar-02 utils]# hwloc-calc $(hwloc-distrib --single 4)
[root_at_amd-dinar-02 utils]# hwloc-distrib --single 4

> > You may consider to add option
> > --all_ancestors (or perhaps ancestors-tree or family-tree)
> > to list the full tree of ancestors objects
> This one might be better in hwloc-info (if we split it out of lstopo) or
> lstopo.
I completely agree.