(switched to email. Please respond via emailed reply-to-all, not via the bugzilla web interface). On Sat, 20 Apr 2013 03:00:30 +0000 (UTC) bugzilla-daemon@xxxxxxxxxxxxxxxxxxx wrote: > https://bugzilla.kernel.org/show_bug.cgi?id=56881 > > Summary: MAP_HUGETLB mmap fails for certain sizes > Product: Memory Management > Version: 2.5 > Kernel Version: 3.5.0-27 Thanks. It's a post-3.4 regression, testcase included. Does someone want to take a look, please? > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: high > Priority: P1 > Component: Other > AssignedTo: akpm@xxxxxxxxxxxxxxxxxxxx > ReportedBy: iceman_dvd@xxxxxxxxx > Regression: No > > > This is on an Ubuntu 12.10 desktop, but the same issue has been found on 12.04 > with 3.5.0 kernel. > See the sample program. An allocation with MAP_HUGETLB consistently fails with > certain sizes, while it succeeds with others. > The allocation sizes are well below the number of free huge pages. > > $ uname -a Linux davide-lnx2 3.5.0-27-generic #46-Ubuntu SMP Mon Mar 25 > 19:58:17 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux > > > # echo 100 > /proc/sys/vm/nr_hugepages > > # cat /proc/meminfo > ... > AnonHugePages: 0 kB > HugePages_Total: 100 > HugePages_Free: 100 > HugePages_Rsvd: 0 > HugePages_Surp: 0 > Hugepagesize: 2048 kB > > > $ ./mmappu $((5 * 2 * 1024 * 1024 - 4096)) > size=10481664 0x9ff000 > hugepage mmap: Invalid argument > > > $ ./mmappu $((5 * 2 * 1024 * 1024 - 4095)) > size=10481665 0x9ff001 > OK! > > > It seems the trigger point is a normal page size. > The same binary works flawlessly in previous kernels. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>