memcg: allocate v1 event percpu only on v1 deployment

Currently memcg->events_percpu gets allocated on v2 deployments.  Let's
move the allocation to v1 only codebase.  This is not needed in v2.

Link: https://lkml.kernel.org/r/20240815050453.1298138-7-shakeel.butt@linux.dev
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 08b7121cf43a52f5786c48fc395e2e5a2af1cf0a..ed170399179acbbcaa29fb0bc8f24de35744500d 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -255,7 +255,6 @@ struct mem_cgroup {
        struct list_head objcg_list;
 
        struct memcg_vmstats_percpu __percpu *vmstats_percpu;
-       struct memcg1_events_percpu __percpu *events_percpu;
 
 #ifdef CONFIG_CGROUP_WRITEBACK
        struct list_head cgwb_list;
@@ -277,6 +276,8 @@ struct mem_cgroup {
        struct page_counter kmem;               /* v1 only */
        struct page_counter tcpmem;             /* v1 only */
 
+       struct memcg1_events_percpu __percpu *events_percpu;
+
        unsigned long soft_limit;
 
        /* protected by memcg_oom_lock */

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 8168a0c965b7178b0edca4666c1137e2320c34a8..ff972a35ecc56061804a4a6d458425102e519017 100644 (file)
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -1442,6 +1442,12 @@ static void mem_cgroup_threshold(struct mem_cgroup *memcg)
        }
 }
 
+/* Cgroup1: threshold notifications & softlimit tree updates */
+struct memcg1_events_percpu {
+       unsigned long nr_page_events;
+       unsigned long targets[MEM_CGROUP_NTARGETS];
+};
+
 static void memcg1_charge_statistics(struct mem_cgroup *memcg, int nr_pages)
 {
        /* pagein of a big page is an event. So, ignore page size */
@@ -3033,6 +3039,19 @@ bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
        return false;
 }
 
+bool memcg1_alloc_events(struct mem_cgroup *memcg)
+{
+       memcg->events_percpu = alloc_percpu_gfp(struct memcg1_events_percpu,
+                                               GFP_KERNEL_ACCOUNT);
+       return !!memcg->events_percpu;
+}
+
+void memcg1_free_events(struct mem_cgroup *memcg)
+{
+       if (memcg->events_percpu)
+               free_percpu(memcg->events_percpu);
+}
+
 static int __init memcg1_init(void)
 {
        int node;

diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index 0a9f3f9c2362092635e677218fa39f06905d96e7..3bb8b3030e619bc08cb0aa076ec1ca480d1dd285 100644 (file)
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -55,12 +55,6 @@ enum mem_cgroup_events_target {
        MEM_CGROUP_NTARGETS,
 };
 
-/* Cgroup1: threshold notifications & softlimit tree updates */
-struct memcg1_events_percpu {
-       unsigned long nr_page_events;
-       unsigned long targets[MEM_CGROUP_NTARGETS];
-};
-
 unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap);
 
 void drain_all_stock(struct mem_cgroup *root_memcg);
@@ -72,21 +66,12 @@ unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item);
 unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item);
 int memory_stat_show(struct seq_file *m, void *v);
 
-static inline bool memcg1_alloc_events(struct mem_cgroup *memcg)
-{
-       memcg->events_percpu = alloc_percpu_gfp(struct memcg1_events_percpu,
-                                               GFP_KERNEL_ACCOUNT);
-       return !!memcg->events_percpu;
-}
-
-static inline void memcg1_free_events(struct mem_cgroup *memcg)
-{
-       if (memcg->events_percpu)
-               free_percpu(memcg->events_percpu);
-}
-
 /* Cgroup v1-specific declarations */
 #ifdef CONFIG_MEMCG_V1
+
+bool memcg1_alloc_events(struct mem_cgroup *memcg);
+void memcg1_free_events(struct mem_cgroup *memcg);
+
 void memcg1_memcg_init(struct mem_cgroup *memcg);
 void memcg1_remove_from_trees(struct mem_cgroup *memcg);
 
@@ -139,6 +124,9 @@ extern struct cftype mem_cgroup_legacy_files[];
 
 #else  /* CONFIG_MEMCG_V1 */
 
+static inline bool memcg1_alloc_events(struct mem_cgroup *memcg) { return true; }
+static inline void memcg1_free_events(struct mem_cgroup *memcg) {}
+
 static inline void memcg1_memcg_init(struct mem_cgroup *memcg) {}
 static inline void memcg1_remove_from_trees(struct mem_cgroup *memcg) {}
 static inline void memcg1_soft_limit_reset(struct mem_cgroup *memcg) {}