Le 11/11/2010 13:08, Jirka Hladky a écrit : > 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.
Right, it's not supported on Linux. > We can perhaps > enhance the parsing to raise an error when --pid and --get are both specified. > It actually depends on the OS. I'll see what I can. > 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? > 0xf...f is a full set (all bit from 0 to infinity are set). It means that the memory binding is set to "near all the memory of the machine". Finding a behavior that works for both NUMA and non-NUMA cases was not easy... > 3) Just a small hint. Fedora 12 is using almost the same kernel as RHEL-6. > Ah good to know, thanks. I am deploying a F12 machine right now to check things. Brice
