From: Srinivasulu Thanneeru <sthanneeru.opensrc@xxxxxxxxxx>
This patch introduces a new attribute called adistance_offset to the
node_devices structure.
Using adistance_offset, a node can be migrated to a targeted tier.
Target tier's adjacent distance(adistance) is calculated by taking the
adistance offset into account.
Signed-off-by: Srinivasulu Thanneeru <sthanneeru.opensrc@xxxxxxxxxx>
Signed-off-by: Ravi Jonnalagadda <ravis.opensrc@xxxxxxxxxx>
---
drivers/base/node.c | 45 ++++++++++++++++++++++++++++++++++++
include/linux/memory-tiers.h | 6 +++++
include/linux/node.h | 1 +
mm/memory-tiers.c | 14 +++++++++++
4 files changed, 66 insertions(+)
diff --git a/drivers/base/node.c b/drivers/base/node.c
index 493d533f8375..1e63c692977b 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -7,6 +7,7 @@
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memory.h>
+#include <linux/memory-tiers.h>
#include <linux/vmstat.h>
#include <linux/notifier.h>
#include <linux/node.h>
@@ -569,11 +570,54 @@ static ssize_t node_read_distance(struct device *dev,
}
static DEVICE_ATTR(distance, 0444, node_read_distance, NULL);
+static ssize_t adistance_offset_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int nid = dev->id;
+ int len = 0;
+
+ /*
+ * buf is currently PAGE_SIZE in length and each node needs 4 chars
+ * at the most (distance + space or newline).
+ */
+ BUILD_BUG_ON(MAX_NUMNODES * 4 > PAGE_SIZE);
+
+ len += sysfs_emit(buf, "%d\n", node_devices[nid]->adistance_offset);
+ return len;
+}
+
+static ssize_t adistance_offset_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ int nid = dev->id;
+ int value, ret;
+
+ ret = kstrtoint(buf, 0, &value);
+
+ if (ret)
+ return ret;
+ if (node_devices[nid]->adistance_offset == value)
+ return size;
+ /*
+ * Request from a node to migrate to a memtier with negative
+ * adistance is not valid.
+ */
+ ret = get_target_memtier_adistance(nid, value);
+ if (ret < 0)
+ return -EINVAL;
+
+ node_devices[nid]->adistance_offset = value;
+ return size;
+}
+static DEVICE_ATTR_RW(adistance_offset);
+
static struct attribute *node_dev_attrs[] = {
&dev_attr_meminfo.attr,
&dev_attr_numastat.attr,
&dev_attr_distance.attr,
&dev_attr_vmstat.attr,
+ &dev_attr_adistance_offset.attr,
NULL
};
@@ -883,6 +927,7 @@ int __register_one_node(int nid)
INIT_LIST_HEAD(&node_devices[nid]->access_list);
node_init_caches(nid);
+ node_devices[nid]->adistance_offset = 0;
return error;
}
diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
index 1e39d27bee41..ff4e7136ab40 100644
--- a/include/linux/memory-tiers.h
+++ b/include/linux/memory-tiers.h
@@ -48,6 +48,7 @@ int mt_calc_adistance(int node, int *adist);
int mt_set_default_dram_perf(int nid, struct node_hmem_attrs *perf,
const char *source);
int mt_perf_to_adistance(struct node_hmem_attrs *perf, int *adist);
+int get_target_memtier_adistance(int node, int adistance_offset);
#ifdef CONFIG_MIGRATION
int next_demotion_node(int node);
void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
@@ -136,5 +137,10 @@ static inline int mt_perf_to_adistance(struct node_hmem_attrs *perf, int *adist)
{
return -EIO;
}
+
+static int get_target_memtier_adistance(int node, int adistance_offset)
+{
+ return 0;
+}
#endif /* CONFIG_NUMA */
#endif /* _LINUX_MEMORY_TIERS_H */
diff --git a/include/linux/node.h b/include/linux/node.h
index 427a5975cf40..fd0f4f3177f8 100644
--- a/include/linux/node.h
+++ b/include/linux/node.h
@@ -83,6 +83,7 @@ static inline void node_set_perf_attrs(unsigned int nid,
struct node {
struct device dev;
struct list_head access_list;
+ int adistance_offset;
#ifdef CONFIG_HMEM_REPORTING
struct list_head cache_attrs;
struct device *cache_dev;
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 8d5291add2bc..a40d4d4383d7 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -167,6 +167,20 @@ static const struct attribute_group *memtier_dev_groups[] = {
NULL
};
+int get_target_memtier_adistance(int node, int adistance_offset)
+{
+ struct memory_dev_type *memtype;
+ int node_adistance;
+
+ memtype = node_memory_types[node].memtype;
+ /*
+ * Calculate the targeted memtier abstract distance from
+ * memtype adistance and node adistance offset.
+ */
+ node_adistance = memtype->adistance + adistance_offset;
+ return node_adistance;
+}
+
static struct memory_tier *find_create_memory_tier(struct memory_dev_type *memtype)
{
int ret;
--
2.25.1
