[PATCH 03/10] mm: mempolicy: promote page to DRAM for MPOL_HYBRID

Yang Shi
2019-03-23T04:45:10Z

With MPOL_HYBRID the memory allocation may end up on non-DRAM node, this
may be not optimal for performance. Promote pages to DRAM with NUMA
balancing for MPOL_HYBRID.

If DRAM nodes are specified, migrate to the specified nodes. If no DRAM
node is specified, migrate to the local DRAM node.

Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
---
mm/mempolicy.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 7d0a432..87bc691 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2339,6 +2339,7 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
struct zoneref *z;
int curnid = page_to_nid(page);
unsigned long pgoff;
+ nodemask_t nmask;
int thiscpu = raw_smp_processor_id();
int thisnid = cpu_to_node(thiscpu);
int polnid = NUMA_NO_NODE;
@@ -2363,7 +2364,24 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
break;

case MPOL_HYBRID:
- /* Fall through */
+ if (node_isset(curnid, pol->v.nodes) &&
+ node_isset(curnid, def_alloc_nodemask))
+ /* The page is already on DRAM node */
+ goto out;
+
+ /*
+ * Promote to the DRAM node specified by the policy, or
+ * the local DRAM node if no DRAM node is specified.
+ */
+ nodes_and(nmask, pol->v.nodes, def_alloc_nodemask);
+
+ z = first_zones_zonelist(
+ node_zonelist(numa_node_id(), GFP_HIGHUSER),
+ gfp_zone(GFP_HIGHUSER),
+ nodes_empty(nmask) ? &def_alloc_nodemask : &nmask);
+ polnid = z->zone->node;
+
+ break;

case MPOL_BIND:

--
1.8.3.1