diff options
| author | Mel Gorman <mgorman@suse.de> | 2013-10-07 11:29:00 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-10-09 12:40:26 +0200 |
| commit | 3a7053b3224f4a8b0e8184166190076593621617 (patch) | |
| tree | dfe404bfbc1306fccbc00f2177becf1482504e45 /kernel/sched/features.h | |
| parent | 745d61476ddb737aad3495fa6d9a8f8c2ee59f86 (diff) | |
sched/numa: Favour moving tasks towards the preferred node
This patch favours moving tasks towards NUMA node that recorded a higher
number of NUMA faults during active load balancing. Ideally this is
self-reinforcing as the longer the task runs on that node, the more faults
it should incur causing task_numa_placement to keep the task running on that
node. In reality a big weakness is that the nodes CPUs can be overloaded
and it would be more efficient to queue tasks on an idle node and migrate
to the new node. This would require additional smarts in the balancer so
for now the balancer will simply prefer to place the task on the preferred
node for a PTE scans which is controlled by the numa_balancing_settle_count
sysctl. Once the settle_count number of scans has complete the schedule
is free to place the task on an alternative node if the load is imbalanced.
[srikar@linux.vnet.ibm.com: Fixed statistics]
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>
[ Tunable and use higher faults instead of preferred. ]
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1381141781-10992-23-git-send-email-mgorman@suse.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/features.h')
| -rw-r--r-- | kernel/sched/features.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/sched/features.h b/kernel/sched/features.h index cba5c616a157..d9278ce2c4b4 100644 --- a/kernel/sched/features.h +++ b/kernel/sched/features.h @@ -67,4 +67,11 @@ SCHED_FEAT(LB_MIN, false) */ #ifdef CONFIG_NUMA_BALANCING SCHED_FEAT(NUMA, false) + +/* + * NUMA_FAVOUR_HIGHER will favor moving tasks towards nodes where a + * higher number of hinting faults are recorded during active load + * balancing. + */ +SCHED_FEAT(NUMA_FAVOUR_HIGHER, true) #endif |