[PATCH v10 1/2] memory tier: dax/kmem: introduce an abstract layer for finding, allocating, and putting memory types

Ho-Ren (Jack) Chuang
2024-04-02T00:17:44Z

Since different memory devices require finding, allocating, and putting
memory types, these common steps are abstracted in this patch,
enhancing the scalability and conciseness of the code.

Signed-off-by: Ho-Ren (Jack) Chuang <horenchuang@bytedance.com>
Reviewed-by: "Huang, Ying" <ying.huang@intel.com>
---
drivers/dax/kmem.c | 20 ++------------------
include/linux/memory-tiers.h | 13 +++++++++++++
mm/memory-tiers.c | 32 ++++++++++++++++++++++++++++++++
3 files changed, 47 insertions(+), 18 deletions(-)

diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 42ee360cf4e3..01399e5b53b2 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -55,21 +55,10 @@ static LIST_HEAD(kmem_memory_types);

static struct memory_dev_type *kmem_find_alloc_memory_type(int adist)
{
- bool found = false;
struct memory_dev_type *mtype;

mutex_lock(&kmem_memory_type_lock);
- list_for_each_entry(mtype, &kmem_memory_types, list) {
- if (mtype->adistance == adist) {
- found = true;
- break;
- }
- }
- if (!found) {
- mtype = alloc_memory_type(adist);
- if (!IS_ERR(mtype))
- list_add(&mtype->list, &kmem_memory_types);
- }
+ mtype = mt_find_alloc_memory_type(adist, &kmem_memory_types);
mutex_unlock(&kmem_memory_type_lock);

return mtype;
@@ -77,13 +66,8 @@ static struct memory_dev_type *kmem_find_alloc_memory_type(int adist)

static void kmem_put_memory_types(void)
{
- struct memory_dev_type *mtype, *mtn;
-
mutex_lock(&kmem_memory_type_lock);
- list_for_each_entry_safe(mtype, mtn, &kmem_memory_types, list) {
- list_del(&mtype->list);
- put_memory_type(mtype);
- }
+ mt_put_memory_types(&kmem_memory_types);
mutex_unlock(&kmem_memory_type_lock);
}

diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
index 69e781900082..a44c03c2ba3a 100644
--- a/include/linux/memory-tiers.h
+++ b/include/linux/memory-tiers.h
@@ -48,6 +48,9 @@ int mt_calc_adistance(int node, int *adist);
int mt_set_default_dram_perf(int nid, struct access_coordinate *perf,
const char *source);
int mt_perf_to_adistance(struct access_coordinate *perf, int *adist);
+struct memory_dev_type *mt_find_alloc_memory_type(int adist,
+ struct list_head *memory_types);
+void mt_put_memory_types(struct list_head *memory_types);
#ifdef CONFIG_MIGRATION
int next_demotion_node(int node);
void node_get_allowed_targets(pg_data_t *pgdat, nodemask_t *targets);
@@ -136,5 +139,15 @@ static inline int mt_perf_to_adistance(struct access_coordinate *perf, int *adis
{
return -EIO;
}
+
+struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types)
+{
+ return NULL;
+}
+
+void mt_put_memory_types(struct list_head *memory_types)
+{
+
+}
#endif /* CONFIG_NUMA */
#endif /* _LINUX_MEMORY_TIERS_H */
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 0537664620e5..974af10cfdd8 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -623,6 +623,38 @@ void clear_node_memory_type(int node, struct memory_dev_type *memtype)
}
EXPORT_SYMBOL_GPL(clear_node_memory_type);

+struct memory_dev_type *mt_find_alloc_memory_type(int adist, struct list_head *memory_types)
+{
+ bool found = false;
+ struct memory_dev_type *mtype;
+
+ list_for_each_entry(mtype, memory_types, list) {
+ if (mtype->adistance == adist) {
+ found = true;
+ break;
+ }
+ }
+ if (!found) {
+ mtype = alloc_memory_type(adist);
+ if (!IS_ERR(mtype))
+ list_add(&mtype->list, memory_types);
+ }
+
+ return mtype;
+}
+EXPORT_SYMBOL_GPL(mt_find_alloc_memory_type);
+
+void mt_put_memory_types(struct list_head *memory_types)
+{
+ struct memory_dev_type *mtype, *mtn;
+
+ list_for_each_entry_safe(mtype, mtn, memory_types, list) {
+ list_del(&mtype->list);
+ put_memory_type(mtype);
+ }
+}
+EXPORT_SYMBOL_GPL(mt_put_memory_types);
+
static void dump_hmem_attrs(struct access_coordinate *coord, const char *prefix)
{
pr_info(