sched/numa: Remove check that skips small VMAs

task_numa_work skips small VMAs. At the time the logic was to reduce the
scanning overhead which was considerable. It is a dubious hack at best.
It would make much more sense to cache where faults have been observed
and only rescan those regions during subsequent PTE scans. Remove this
hack as motivation to do it properly in the future.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Reviewed-by: Rik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-29-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 3383079b1508446734f9b75573bdca6aa5e6af8a..862d20d02e5c93e92da53f4f2131e971d83b38d8 100644 (file)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1127,10 +1127,6 @@ void task_numa_work(struct callback_head *work)
                if (!vma_migratable(vma))
                        continue;
 
-               /* Skip small VMAs. They are not likely to be of relevance */
-               if (vma->vm_end - vma->vm_start < HPAGE_SIZE)
-                       continue;
-
                do {
                        start = max(start, vma->vm_start);
                        end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);