[PATCH v5 5/9] mm/demotion/dax/kmem: Set node's memory tier to MEMORY_TIER_PMEM

["Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>]

By default, all nodes are assigned to DEFAULT_MEMORY_TIER which
is memory tier 1 which is designated for nodes with DRAM, so it
is not the right tier for dax devices.

Set dax kmem device node's tier to MEMORY_TIER_PMEM, In future,
support should be added to distinguish the dax-devices which should
not be MEMORY_TIER_PMEM and right memory tier should be set for them.

Signed-off-by: Jagdish Gediya <jvgediya@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
 drivers/dax/kmem.c | 4 ++++
 mm/memory-tiers.c  | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index a37622060fff..7a11c387fbbc 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -11,6 +11,7 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
+#include <linux/memory-tiers.h>
 #include "dax-private.h"
 #include "bus.h"
 
@@ -147,6 +148,9 @@ static int dev_dax_kmem_probe(struct dev_dax *dev_dax)
 
 	dev_set_drvdata(dev, data);
 
+#ifdef CONFIG_TIERED_MEMORY
+	node_set_memory_tier(numa_node, MEMORY_TIER_PMEM);
+#endif
 	return 0;
 
 err_request_mem:
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 0d05c0bfb79b..9c82cf4c4bca 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -364,6 +364,7 @@ int node_set_memory_tier(int node, int tier)
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(node_set_memory_tier);
 
 /**
  * next_demotion_node() - Get the next node in the demotion path
-- 
2.36.1