On Thursday, November 11, 2010 11:11:31 am Brice Goglin wrote: > Le 11/11/2010 02:31, Samuel Thibault a écrit : > >> get_mempolicy: Invalid argument > >> hwloc_get_membind failed (errno 22 Invalid argument) > > > > Could you try to increase the value of max_os_index? > > > > I can see in the kernel source code the following in sys_get_mempolicy: > > if (nmask != NULL && maxnode < MAX_NUMNODES) > > > > return -EINVAL; > > > > and MAX_NUMNODES depends on .config ... > > And indeed MAX_NUMNODES is (1<<CONFIG_NODES_SHIFT) and > CONFIG_NODES_SHIFT=9 on rhel6 kernels. We pass a single ulong to the > kernel, so it's not large enough to store 1<<9 bits. We couldn't > reproduce on Debian and RHEL5 since NODE_SHIFT=6 there. > > We had to loop until we found the kernel NR_CPUS for sched_getaffinity, > we can do the same to find the kernel MAX_NUMNODES for get_mempolicy. > The attached patch may help. Only slightly tested obviously since I > don't have any kernel causing the problem. > > Brice
Hi Brice, thanks for the quick patch. I have tested it and it works! :-) $ utils/hwloc-bind --membind node:1 --mempolicy interleave -- utils/hwloc-bind --get --membind 0x0000aaaa (interleave) I have couple of questions: 1) Does the option --get works together with --pid ? Like finding out mempolicy for any pid? I don't think that get_mempolicy supports this. We can perhaps enhance the parsing to raise an error when --pid and --get are both specified. 2) This might be a dumb question - I have tried --get on my laptop which is running Fedora-12. It's one socket system with NUMA enabled - there is however only node#0. I know that it's nonsense. But still, you can use this to run some tests I'm quite puzzled by the following output: $utils/hwloc-bind --membind node:0 --mempolicy interleave -- utils/hwloc-bind --get --membind 0xf...f (interleave) What does "0xf...f" mean? 3) Just a small hint. Fedora 12 is using almost the same kernel as RHEL-6. Thanks for looking into this!!! Cheers Jirka
