Messages in this thread |  | | Date | Tue, 03 Dec 2013 18:07:06 -0500 | From | Rik van Riel <> | Subject | Re: [PATCH 14/15] mm: numa: Flush TLB if NUMA hinting faults race with PTE scan update |
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On 12/03/2013 03:52 AM, Mel Gorman wrote: > NUMA PTE updates and NUMA PTE hinting faults can race against each other. The > setting of the NUMA bit defers the TLB flush to reduce overhead. NUMA > hinting faults do not flush the TLB as X86 at least does not cache TLB > entries for !present PTEs. However, in the event that the two race a NUMA > hinting fault may return with the TLB in an inconsistent state between > different processors. This patch detects potential for races between the > NUMA PTE scanner and fault handler and will flush the TLB for the affected > range if there is a race. > > Signed-off-by: Mel Gorman <mgorman@suse.de>
> diff --git a/mm/migrate.c b/mm/migrate.c > index 5dfd552..ccc814b 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1662,6 +1662,39 @@ void wait_migrate_huge_page(struct anon_vma *anon_vma, pmd_t *pmd) > smp_rmb(); > } > > +unsigned long numa_fault_prepare(struct mm_struct *mm) > +{ > + /* Paired with task_numa_work */ > + smp_rmb(); > + return mm->numa_next_reset; > +}
The patch that introduces mm->numa_next_reset, and the patch that increments it, seem to be missing from your series...
-- All rights reversed
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