I am trying to use hwloc on a Blue Gene/Q. Building
and installing worked fine, and it reports the system
configuration fine as well (i.e. it shows all PUs). However,
when I try to inquire the thread/core bindings, hwloc crashes
with an error in libc's free(). This is both with 1.6 and
The error occurs apparently in CPU_FREE called from
Does this ring a bell with anyone? I know this is
not enough information to debug things, but do you have any
pointers for things to look at?
I remember reading somewhere that the last bit in
a cpu_set_t cannot be used. A Blue Gene/Q has 64 PUs, and may
be using 64-bit integers to hold cpu_set_t data. Could this be
My goal is to examine and experiment with
thread/core bindings with OpenMP to improve performance.