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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
parent6fe6b2d6dabf392aceb3ad3a5e859b46a04465c6 (diff)
downloadop-kernel-dev-fc3147245d193bd0f57307859c698fa28a20b0fe.zip
op-kernel-dev-fc3147245d193bd0f57307859c698fa28a20b0fe.tar.gz
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>
-rw-r--r--include/linux/mempolicy.h1
-rw-r--r--kernel/sched/fair.c2
-rw-r--r--mm/mempolicy.c24
3 files changed, 26 insertions, 1 deletions
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index da6716b..ea4d249 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -136,6 +136,7 @@ struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
struct mempolicy *get_vma_policy(struct task_struct *tsk,
struct vm_area_struct *vma, unsigned long addr);
+bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma);
extern void numa_default_policy(void);
extern void numa_policy_init(void);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 61ec0d4..d98175d 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -1130,7 +1130,7 @@ void task_numa_work(struct callback_head *work)
vma = mm->mmap;
}
for (; vma; vma = vma->vm_next) {
- if (!vma_migratable(vma))
+ if (!vma_migratable(vma) || !vma_policy_mof(p, vma))
continue;
do {
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 196d8da..0e895a2 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;
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