On Fri, Aug 24, 2012 at 1:17 AM, Gerald Schaefer <[email protected]> wrote: > This adds a check to hugepage_madvise(), to refuse MADV_HUGEPAGE > if VM_NOHUGEPAGE is set in mm->def_flags. On System z, 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 <[email protected]> > --- > mm/huge_memory.c | 4 ++++ > 1 file changed, 4 insertions(+) > > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1464,6 +1464,8 @@ out: > int hugepage_madvise(struct vm_area_struct *vma, > unsigned long *vm_flags, int advice) > { > + struct mm_struct *mm = vma->vm_mm; > + > switch (advice) { > case MADV_HUGEPAGE: > /* > @@ -1471,6 +1473,8 @@ int hugepage_madvise(struct vm_area_stru > */ > if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP)) > return -EINVAL; > + if (mm->def_flags & VM_NOHUGEPAGE) > + return -EINVAL;
Looks ifdefinery needed for s390 to wrap the added check, and a brief comment? > *vm_flags &= ~VM_NOHUGEPAGE; > *vm_flags |= VM_HUGEPAGE; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
