The patch titled
Subject: mm/demotion: expose memory tier details via sysfs
has been added to the -mm mm-unstable branch. Its filename is
mm-demotion-expose-memory-tier-details-via-sysfs.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-demotion-expose-memory-tier-details-via-sysfs.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx>
Subject: mm/demotion: expose memory tier details via sysfs
Date: Mon, 29 Aug 2022 11:37:45 +0530
This patch adds /sys/devices/virtual/memory_tiering/ where all memory tier
related details can be found. All allocated memory tiers will be listed
there as /sys/devices/virtual/memory_tiering/memory_tierN/
The nodes which are part of a specific memory tier can be listed via
/sys/devices/virtual/memory_tiering/memory_tierN/nodes
The abstract distance range value of a specific memory tier can be listed
via /sys/devices/virtual/memory_tiering/memory_tierN/abstract_distance
A directory hierarchy looks like
:/sys/devices/virtual/memory_tiering$ tree memory_tier4/
memory_tier4/
â??â??â?? abstract_distance
â??â??â?? nodes
â??â??â?? subsystem -> ../../../../bus/memory_tiering
â??â??â?? uevent
All toptier nodes are listed via
/sys/devices/virtual/memory_tiering/toptier_nodes
:/sys/devices/virtual/memory_tiering$ cat toptier_nodes
0,2
:/sys/devices/virtual/memory_tiering$ cat memory_tier4/nodes
0,2
:/sys/devices/virtual/memory_tiering$ cat memory_tier4/abstract_distance
512 - 639
Link: https://lkml.kernel.org/r/20220829060745.287468-1-aneesh.kumar@xxxxxxxxxxxxx
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-kernel-mm-memory-tiers | 41 ++
mm/memory-tiers.c | 155 ++++++++--
2 files changed, 174 insertions(+), 22 deletions(-)
--- /dev/null
+++ a/Documentation/ABI/testing/sysfs-kernel-mm-memory-tiers
@@ -0,0 +1,41 @@
+What: /sys/devices/virtual/memory_tiering/
+Date: August 2022
+Contact: Linux memory management mailing list <linux-mm@xxxxxxxxx>
+Description: A collection of all the memory tiers allocated.
+
+ Individual memory tier details are contained in subdirectories
+ named by the abstract distance of the memory tier.
+
+ /sys/devices/virtual/memory_tiering/memory_tierN/
+
+
+What: /sys/devices/virtual/memory_tiering/memory_tierN/
+ /sys/devices/virtual/memory_tiering/memory_tierN/abstract_distance
+ /sys/devices/virtual/memory_tiering/memory_tierN/nodes
+Date: August 2022
+Contact: Linux memory management mailing list <linux-mm@xxxxxxxxx>
+Description: Directory with details of a specific memory tier
+
+ This is the directory containing information about a particular
+ memory tier, memtierN, where N is derived based on abstract distance.
+
+ A smaller value of N implies a higher (faster) memory tier in the
+ hierarchy.
+
+ abstract_distance: The abstract distance range this specific memory
+ tier maps to.
+
+ nodes: NUMA nodes that are part of this memory tier.
+
+
+What: /sys/devices/virtual/memory_tiering/toptier_nodes
+Date: August 2022
+Contact: Linux memory management mailing list <linux-mm@xxxxxxxxx>
+Description: Toptier node mask
+
+ A toptier is defined as the memory tier from which memory promotion
+ is not done by the kernel.
+
+ toptier_nodes: NUMA nodes that are part of all the memory tiers
+ above a topier tier.
+
--- a/mm/memory-tiers.c~mm-demotion-expose-memory-tier-details-via-sysfs
+++ a/mm/memory-tiers.c
@@ -19,6 +19,7 @@ struct memory_tier {
* adistance_start .. adistance_start + MEMTIER_CHUNK_SIZE
*/
int adistance_start;
+ struct device dev;
/* All the nodes that are part of all the lower memory tiers. */
nodemask_t lower_tier_mask;
};
@@ -36,6 +37,13 @@ static DEFINE_MUTEX(memory_tier_lock);
static LIST_HEAD(memory_tiers);
static struct node_memory_type_map node_memory_types[MAX_NUMNODES];
static struct memory_dev_type *default_dram_type;
+
+#define to_memory_tier(device) container_of(device, struct memory_tier, dev)
+static struct bus_type memory_tier_subsys = {
+ .name = "memory_tiering",
+ .dev_name = "memory_tier",
+};
+
#ifdef CONFIG_MIGRATION
static int top_tier_adistance;
/*
@@ -98,8 +106,73 @@ static int top_tier_adistance;
static struct demotion_nodes *node_demotion __read_mostly;
#endif /* CONFIG_MIGRATION */
+static __always_inline nodemask_t get_memtier_nodemask(struct memory_tier *memtier)
+{
+ nodemask_t nodes = NODE_MASK_NONE;
+ struct memory_dev_type *memtype;
+
+ list_for_each_entry(memtype, &memtier->memory_types, tier_sibiling)
+ nodes_or(nodes, nodes, memtype->nodes);
+
+ return nodes;
+}
+
+static void memory_tier_device_release(struct device *dev)
+{
+ struct memory_tier *tier = to_memory_tier(dev);
+ /*
+ * synchronize_rcu in clear_node_memory_tier makes sure
+ * we don't have rcu access to this memory tier.
+ */
+ kfree(tier);
+}
+
+static ssize_t nodes_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int ret;
+ nodemask_t nmask;
+
+ mutex_lock(&memory_tier_lock);
+ nmask = get_memtier_nodemask(to_memory_tier(dev));
+ ret = sysfs_emit(buf, "%*pbl\n", nodemask_pr_args(&nmask));
+ mutex_unlock(&memory_tier_lock);
+ return ret;
+}
+static DEVICE_ATTR_RO(nodes);
+
+static ssize_t abstract_distance_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int ret;
+ struct memory_tier *memtier = to_memory_tier(dev);
+
+ mutex_lock(&memory_tier_lock);
+ ret = sysfs_emit(buf, "%d - %d\n", memtier->adistance_start,
+ memtier->adistance_start + MEMTIER_CHUNK_SIZE - 1);
+ mutex_unlock(&memory_tier_lock);
+ return ret;
+}
+static DEVICE_ATTR_RO(abstract_distance);
+
+static struct attribute *memtier_dev_attrs[] = {
+ &dev_attr_nodes.attr,
+ &dev_attr_abstract_distance.attr,
+ NULL
+};
+
+static const struct attribute_group memtier_dev_group = {
+ .attrs = memtier_dev_attrs,
+};
+
+static const struct attribute_group *memtier_dev_groups[] = {
+ &memtier_dev_group,
+ NULL
+};
+
static struct memory_tier *find_create_memory_tier(struct memory_dev_type *memtype)
{
+ int ret;
bool found_slot = false;
struct memory_tier *memtier, *new_memtier;
int adistance = memtype->adistance;
@@ -123,15 +196,14 @@ static struct memory_tier *find_create_m
list_for_each_entry(memtier, &memory_tiers, list) {
if (adistance == memtier->adistance_start) {
- list_add(&memtype->tier_sibiling, &memtier->memory_types);
- return memtier;
+ goto link_memtype;
} else if (adistance < memtier->adistance_start) {
found_slot = true;
break;
}
}
- new_memtier = kmalloc(sizeof(struct memory_tier), GFP_KERNEL);
+ new_memtier = kzalloc(sizeof(struct memory_tier), GFP_KERNEL);
if (!new_memtier)
return ERR_PTR(-ENOMEM);
@@ -142,8 +214,23 @@ static struct memory_tier *find_create_m
list_add_tail(&new_memtier->list, &memtier->list);
else
list_add_tail(&new_memtier->list, &memory_tiers);
- list_add(&memtype->tier_sibiling, &new_memtier->memory_types);
- return new_memtier;
+
+ new_memtier->dev.id = adistance >> MEMTIER_CHUNK_BITS;
+ new_memtier->dev.bus = &memory_tier_subsys;
+ new_memtier->dev.release = memory_tier_device_release;
+ new_memtier->dev.groups = memtier_dev_groups;
+
+ ret = device_register(&new_memtier->dev);
+ if (ret) {
+ list_del(&memtier->list);
+ put_device(&memtier->dev);
+ return ERR_PTR(ret);
+ }
+ memtier = new_memtier;
+
+link_memtype:
+ list_add(&memtype->tier_sibiling, &memtier->memory_types);
+ return memtier;
}
static struct memory_tier *__node_get_memory_tier(int node)
@@ -275,17 +362,6 @@ static void disable_all_demotion_targets
synchronize_rcu();
}
-static __always_inline nodemask_t get_memtier_nodemask(struct memory_tier *memtier)
-{
- nodemask_t nodes = NODE_MASK_NONE;
- struct memory_dev_type *memtype;
-
- list_for_each_entry(memtype, &memtier->memory_types, tier_sibiling)
- nodes_or(nodes, nodes, memtype->nodes);
-
- return nodes;
-}
-
/*
* Find an automatic demotion target for all memory
* nodes. Failing here is OK. It might just indicate
@@ -432,11 +508,7 @@ static struct memory_tier *set_node_memo
static void destroy_memory_tier(struct memory_tier *memtier)
{
list_del(&memtier->list);
- /*
- * synchronize_rcu in clear_node_memory_tier makes sure
- * we don't have rcu access to this memory tier.
- */
- kfree(memtier);
+ device_unregister(&memtier->dev);
}
static bool clear_node_memory_tier(int node)
@@ -563,11 +635,50 @@ static int __meminit memtier_hotplug_cal
return notifier_from_errno(0);
}
+static ssize_t toptier_nodes_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int ret;
+ nodemask_t nmask, top_tier_mask = NODE_MASK_NONE;
+ struct memory_tier *memtier = to_memory_tier(dev);
+
+ mutex_lock(&memory_tier_lock);
+ list_for_each_entry(memtier, &memory_tiers, list) {
+ if (memtier->adistance_start >= top_tier_adistance)
+ break;
+ nmask = get_memtier_nodemask(memtier);
+ nodes_or(top_tier_mask, top_tier_mask, nmask);
+ }
+
+ ret = sysfs_emit(buf, "%*pbl\n", nodemask_pr_args(&top_tier_mask));
+ mutex_unlock(&memory_tier_lock);
+ return ret;
+}
+static DEVICE_ATTR_RO(toptier_nodes);
+
+static struct attribute *memtier_subsys_attrs[] = {
+ &dev_attr_toptier_nodes.attr,
+ NULL
+};
+
+static const struct attribute_group memtier_subsys_group = {
+ .attrs = memtier_subsys_attrs,
+};
+
+static const struct attribute_group *memtier_subsys_groups[] = {
+ &memtier_subsys_group,
+ NULL
+};
+
static int __init memory_tier_init(void)
{
- int node;
+ int ret, node;
struct memory_tier *memtier;
+ ret = subsys_virtual_register(&memory_tier_subsys, memtier_subsys_groups);
+ if (ret)
+ panic("%s() failed to register memory tier subsystem\n", __func__);
+
#ifdef CONFIG_MIGRATION
node_demotion = kcalloc(nr_node_ids, sizeof(struct demotion_nodes),
GFP_KERNEL);
_
Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxx are
mm-demotion-add-support-for-explicit-memory-tiers.patch
mm-demotion-move-memory-demotion-related-code.patch
mm-demotion-add-hotplug-callbacks-to-handle-new-numa-node-onlined.patch
mm-demotion-add-hotplug-callbacks-to-handle-new-numa-node-onlined-fix.patch
mm-demotion-dax-kmem-set-nodes-abstract-distance-to-memtier_default_dax_adistance.patch
mm-demotion-dax-kmem-set-nodes-abstract-distance-to-memtier_default_dax_adistance-fix.patch
mm-demotion-build-demotion-targets-based-on-explicit-memory-tiers.patch
mm-demotion-add-pg_data_t-member-to-track-node-memory-tier-details.patch
mm-demotion-drop-memtier-from-memtype.patch
mm-demotion-update-node_is_toptier-to-work-with-memory-tiers.patch
lib-nodemask-optimize-node_random-for-nodemask-with-single-numa-node.patch
mm-demotion-expose-memory-tier-details-via-sysfs.patch
