thp: make MADV_HUGEPAGE check for mm->def_flags
authorGerald Schaefer <gerald.schaefer@de.ibm.com>
Mon, 8 Oct 2012 23:30:12 +0000 (16:30 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 9 Oct 2012 07:22:30 +0000 (16:22 +0900)
commit8e72033f2a489b6c98c4e3c7cc281b1afd6cb85c
tree9ac78daf640471e00f3f0fbe22f6c24fb95b8817
parent46dcde735c9d8953bbd8d105ca6779e5b5300c28
thp: make MADV_HUGEPAGE check for mm->def_flags

This adds a check to hugepage_madvise(), to refuse MADV_HUGEPAGE if
VM_NOHUGEPAGE is set in mm->def_flags.  On s390, the VM_NOHUGEPAGE flag
will be set in mm->def_flags for kvm processes, to prevent any future thp
mappings.  In order to also prevent MADV_HUGEPAGE on such an mm,
hugepage_madvise() should check mm->def_flags.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/huge_memory.c