FWIW it's worth, it's a "bug" in valgrind. The manpage of mbind does not exactly match the kernel requirements on mbind parameters. And valgrind fails at respecting the manpage anyway. See https://bugs.kde.org/show_bug.cgi?id=280083 for the mess...


Le 13/08/2011 15:07, Brice Goglin a écrit :
I think I am seeing this too on a custom program, so probably not your application's fault.

Le 13/08/2011 10:37, Gabriele Fatigati a écrit :

Dearhwloc users and developers,

I'm using hwloc 1.2 stable version Intel 11 compiled and checking my little application with valgrind 3.5.

My app calls hwloc_set_area_membind_nodeset() function from a OpenMP thread:

hwloc_set_area_membind_nodeset(topology, mem, 10000, nodeset, HWLOC_MEMBIND_BIND, HWLOC_MEMBIND_THREAD | HWLOC_MEMBIND_STRICT | HWLOC_MEMBIND_NOCPUBIND ) 

membind seems to work well, but valgrind give me a follow warning:

==2904== Syscall param mbind(nodemask) points to unaddressable byte(s)
==2904==    at 0x4FF33C1: syscall6 (in /usr/lib64/libnuma.so.1)
==2904==    by 0x4FF3436: mbind (in /usr/lib64/libnuma.so.1)
==2904==    by 0x4C208AC: hwloc_linux_set_area_membind (topology-linux.c:1071)
==2904==    by 0x4C1AC3E: hwloc_set_area_membind_nodeset (bind.c:396)
==2904==    by 0x402165: bind_memory_tonode (main.c:97)
==2904==  Address 0x5a64978 is 0 bytes after a block of size 8 alloc'd
==2904==    at 0x4A05140: calloc (vg_replace_malloc.c:418)
==2904==    by 0x4C20646: hwloc_linux_membind_mask_from_nodeset (topology-linux.c:996)
==2904==    by 0x4C2083E: hwloc_linux_set_area_membind (topology-linux.c:1054)
==2904==    by 0x4C1AC3E: hwloc_set_area_membind_nodeset (bind.c:396)
==2904==    by 0x401CBB: bind_memory_tonode (main.c:97)

valgrind has  --tool=memcheck --leak-check=full  exec flags.

It give me the same warning also with just one byte memory bound.

Is it a hwloc warning or my applications warning?

Thanks in forward.

Ing. Gabriele Fatigati

HPC specialist

SuperComputing Applications and Innovation Department

Via Magnanelli 6/3, Casalecchio di Reno (BO) Italy

www.cineca.it                    Tel:   +39 051 6171722

g.fatigati [AT] cineca.it          
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