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authorMel Gorman <mgorman@suse.de>2013-10-07 11:29:09 +0100
committerIngo Molnar <mingo@kernel.org>2013-10-09 12:40:38 +0200
commitfc3147245d193bd0f57307859c698fa28a20b0fe (patch)
treed1c6339ab156fc1f1419fe62164dfd1947cec14d /mm/mempolicy.c
parent6fe6b2d6dabf392aceb3ad3a5e859b46a04465c6 (diff)
mm: numa: Limit NUMA scanning to migrate-on-fault VMAs
There is a 90% regression observed with a large Oracle performance test on a 4 node system. Profiles indicated that the overhead was due to contention on sp_lock when looking up shared memory policies. These policies do not have the appropriate flags to allow them to be automatically balanced so trapping faults on them is pointless. This patch skips VMAs that do not have MPOL_F_MOF set. [riel@redhat.com: Initial patch] Signed-off-by: Mel Gorman <mgorman@suse.de> Reported-and-tested-by: Joe Mario <jmario@redhat.com> 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/1381141781-10992-32-git-send-email-mgorman@suse.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/mempolicy.c')
-rw-r--r--mm/mempolicy.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 196d8da2b657..0e895a2eed5f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1679,6 +1679,30 @@ struct mempolicy *get_vma_policy(struct task_struct *task,
return pol;
}
+bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma)
+{
+ struct mempolicy *pol = get_task_policy(task);
+ if (vma) {
+ if (vma->vm_ops && vma->vm_ops->get_policy) {
+ bool ret = false;
+
+ pol = vma->vm_ops->get_policy(vma, vma->vm_start);
+ if (pol && (pol->flags & MPOL_F_MOF))
+ ret = true;
+ mpol_cond_put(pol);
+
+ return ret;
+ } else if (vma->vm_policy) {
+ pol = vma->vm_policy;
+ }
+ }
+
+ if (!pol)
+ return default_policy.flags & MPOL_F_MOF;
+
+ return pol->flags & MPOL_F_MOF;
+}
+
static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
{
enum zone_type dynamic_policy_zone = policy_zone;