On Tue, Dec 03, 2013 at 06:07:06PM -0500, Rik van Riel wrote: > 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 <[email protected]> > > > 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... >
Damn. s/numa_next_reset/numa_next_scan/ in that patch -- Mel Gorman SUSE Labs -- 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/
