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-rw-r--r--mm/filemap.c2
-rw-r--r--mm/memcontrol.c40
2 files changed, 38 insertions, 4 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index b04ba896aac9..48cd16c54e86 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -816,7 +816,7 @@ void replace_page_cache_folio(struct folio *old, struct folio *new)
new->mapping = mapping;
new->index = offset;
- mem_cgroup_migrate(old, new);
+ mem_cgroup_replace_folio(old, new);
xas_lock_irq(&xas);
xas_store(&xas, new);
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b3e40a59f732..135d6637afe5 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -7292,16 +7292,17 @@ void __mem_cgroup_uncharge_list(struct list_head *page_list)
}
/**
- * mem_cgroup_migrate - Charge a folio's replacement.
+ * mem_cgroup_replace_folio - Charge a folio's replacement.
* @old: Currently circulating folio.
* @new: Replacement folio.
*
* Charge @new as a replacement folio for @old. @old will
- * be uncharged upon free.
+ * be uncharged upon free. This is only used by the page cache
+ * (in replace_page_cache_folio()).
*
* Both folios must be locked, @new->mapping must be set up.
*/
-void mem_cgroup_migrate(struct folio *old, struct folio *new)
+void mem_cgroup_replace_folio(struct folio *old, struct folio *new)
{
struct mem_cgroup *memcg;
long nr_pages = folio_nr_pages(new);
@@ -7340,6 +7341,39 @@ void mem_cgroup_migrate(struct folio *old, struct folio *new)
local_irq_restore(flags);
}
+/**
+ * mem_cgroup_migrate - Transfer the memcg data from the old to the new folio.
+ * @old: Currently circulating folio.
+ * @new: Replacement folio.
+ *
+ * Transfer the memcg data from the old folio to the new folio for migration.
+ * The old folio's data info will be cleared. Note that the memory counters
+ * will remain unchanged throughout the process.
+ *
+ * Both folios must be locked, @new->mapping must be set up.
+ */
+void mem_cgroup_migrate(struct folio *old, struct folio *new)
+{
+ struct mem_cgroup *memcg;
+
+ VM_BUG_ON_FOLIO(!folio_test_locked(old), old);
+ VM_BUG_ON_FOLIO(!folio_test_locked(new), new);
+ VM_BUG_ON_FOLIO(folio_test_anon(old) != folio_test_anon(new), new);
+ VM_BUG_ON_FOLIO(folio_nr_pages(old) != folio_nr_pages(new), new);
+
+ if (mem_cgroup_disabled())
+ return;
+
+ memcg = folio_memcg(old);
+ VM_WARN_ON_ONCE_FOLIO(!memcg, old);
+ if (!memcg)
+ return;
+
+ /* Transfer the charge and the css ref */
+ commit_charge(new, memcg);
+ old->memcg_data = 0;
+}
+
DEFINE_STATIC_KEY_FALSE(memcg_sockets_enabled_key);
EXPORT_SYMBOL(memcg_sockets_enabled_key);