Commit 7766cf7a authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Andrew Morton

mm/demotion: add pg_data_t member to track node memory tier details

Also update different helpes to use NODE_DATA()->memtier.  Since node
specific memtier can change based on the reassignment of NUMA node to a
different memory tiers, accessing NODE_DATA()->memtier needs to happen
under an rcu read lock or memory_tier_lock.

Link: https://lkml.kernel.org/r/20220818131042.113280-7-aneesh.kumar@linux.ibm.comSigned-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: default avatar"Huang, Ying" <ying.huang@intel.com>
Acked-by: default avatarWei Xu <weixugc@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Bharata B Rao <bharata@amd.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hesham Almatary <hesham.almatary@huawei.com>
Cc: Jagdish Gediya <jvgediya.oss@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 6c542ab7
......@@ -1246,6 +1246,9 @@ typedef struct pglist_data {
/* Per-node vmstats */
struct per_cpu_nodestat __percpu *per_cpu_nodestats;
atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
#ifdef CONFIG_NUMA
struct memory_tier __rcu *memtier;
#endif
} pg_data_t;
#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
......
......@@ -4,6 +4,7 @@
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <linux/memory.h>
#include <linux/mmzone.h>
#include <linux/memory-tiers.h>
#include "internal.h"
......@@ -141,12 +142,18 @@ static struct memory_tier *find_create_memory_tier(struct memory_dev_type *memty
static struct memory_tier *__node_get_memory_tier(int node)
{
struct memory_dev_type *memtype;
pg_data_t *pgdat;
memtype = node_memory_types[node];
if (memtype && node_isset(node, memtype->nodes))
return memtype->memtier;
return NULL;
pgdat = NODE_DATA(node);
if (!pgdat)
return NULL;
/*
* Since we hold memory_tier_lock, we can avoid
* RCU read locks when accessing the details. No
* parallel updates are possible here.
*/
return rcu_dereference_check(pgdat->memtier,
lockdep_is_held(&memory_tier_lock));
}
#ifdef CONFIG_MIGRATION
......@@ -309,6 +316,8 @@ static struct memory_tier *set_node_memory_tier(int node)
{
struct memory_tier *memtier;
struct memory_dev_type *memtype;
pg_data_t *pgdat = NODE_DATA(node);
lockdep_assert_held_once(&memory_tier_lock);
......@@ -320,24 +329,45 @@ static struct memory_tier *set_node_memory_tier(int node)
memtype = node_memory_types[node].memtype;
node_set(node, memtype->nodes);
memtier = find_create_memory_tier(memtype);
if (!IS_ERR(memtier))
rcu_assign_pointer(pgdat->memtier, memtier);
return memtier;
}
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);
}
static bool clear_node_memory_tier(int node)
{
bool cleared = false;
pg_data_t *pgdat;
struct memory_tier *memtier;
pgdat = NODE_DATA(node);
if (!pgdat)
return false;
/*
* Make sure that anybody looking at NODE_DATA who finds
* a valid memtier finds memory_dev_types with nodes still
* linked to the memtier. We achieve this by waiting for
* rcu read section to finish using synchronize_rcu.
* This also enables us to free the destroyed memory tier
* with kfree instead of kfree_rcu
*/
memtier = __node_get_memory_tier(node);
if (memtier) {
struct memory_dev_type *memtype;
rcu_assign_pointer(pgdat->memtier, NULL);
synchronize_rcu();
memtype = node_memory_types[node].memtype;
node_clear(node, memtype->nodes);
if (nodes_empty(memtype->nodes)) {
......
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