Messages in this thread | | | Date | Sun, 19 Jan 2014 01:49:57 +0200 | From | "Kirill A. Shutemov" <> | Subject | Re: [RFC PATCHv2 2/2] Change khugepaged to respect MMF_THP_DISABLE flag |
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On Thu, Jan 16, 2014 at 03:01:44PM -0600, Alex Thorlton wrote: > This just adds a simple check to get khugepaged to behave > appropriately when MMF_THP_DISABLE is set. > > Signed-off-by: Alex Thorlton <athorlton@sgi.com> > Cc: Ingo Molnar <mingo@redhat.com> > Cc: Peter Zijlstra <peterz@infradead.org> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> > Cc: Rik van Riel <riel@redhat.com> > Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> > Cc: Oleg Nesterov <oleg@redhat.com> > Cc: "Eric W. Biederman" <ebiederm@xmission.com> > Cc: Andy Lutomirski <luto@amacapital.net> > Cc: Al Viro <viro@zeniv.linux.org.uk> > Cc: Kees Cook <keescook@chromium.org> > Cc: Andrea Arcangeli <aarcange@redhat.com> > Cc: linux-kernel@vger.kernel.org > > --- > mm/huge_memory.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 9c0b172..3cfe6b4 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -2049,7 +2049,8 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm, > > static inline int khugepaged_test_exit(struct mm_struct *mm) > { > - return atomic_read(&mm->mm_users) == 0; > + return atomic_read(&mm->mm_users) == 0 || > + (mm->flags & MMF_THP_DISABLE_MASK);
__khugepaged_enter() has VM_BUG_ON(khugepaged_test_exit(mm)). Do we really want to crash there if MMF_THP_DISABLE is set?
-- Kirill A. Shutemov
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