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

Aneesh Kumar K.V
2022-06-03T13:44:37Z

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