mm: memcg: factor out legacy socket memory accounting code

Move out the legacy cgroup v1 socket memory accounting code into
mm/memcontrol-v1.c.

This commit introduces three new functions: memcg1_tcpmem_active(),
memcg1_charge_skmem() and memcg1_uncharge_skmem(), which contain all
cgroup v1-specific code and become trivial if CONFIG_MEMCG_V1 isn't set.

Note, that !!memcg->tcpmem_pressure check in
mem_cgroup_under_socket_pressure() can't be easily moved into
memcontrol-v1.h without including memcontrol-v1.h from memcontrol.h which
isn't a good idea, so it's better to just #ifdef it.

Link: https://lkml.kernel.org/r/20240628210317.272856-3-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Acked-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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 796cfa8423461b918a5015b9dc30d70ce000e047..44ab6394c9ed752332299a10f682c7d7d061d8d9 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1650,8 +1650,10 @@ void mem_cgroup_sk_alloc(struct sock *sk);
 void mem_cgroup_sk_free(struct sock *sk);
 static inline bool mem_cgroup_under_socket_pressure(struct mem_cgroup *memcg)
 {
+#ifdef CONFIG_MEMCG_V1
        if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
                return !!memcg->tcpmem_pressure;
+#endif /* CONFIG_MEMCG_V1 */
        do {
                if (time_before(jiffies, READ_ONCE(memcg->socket_pressure)))
                        return true;

diff --git a/mm/memcontrol-v1.c b/mm/memcontrol-v1.c
index 34579085559f93c5f9a4d4a241407d817deab4aa..c1d5076927a6da0bec3e0967f281f08a424b60fb 100644 (file)
--- a/mm/memcontrol-v1.c
+++ b/mm/memcontrol-v1.c
@@ -2925,6 +2925,23 @@ void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages)
 }
 #endif /* CONFIG_MEMCG_KMEM */
 
+bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+                        gfp_t gfp_mask)
+{
+       struct page_counter *fail;
+
+       if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) {
+               memcg->tcpmem_pressure = 0;
+               return true;
+       }
+       memcg->tcpmem_pressure = 1;
+       if (gfp_mask & __GFP_NOFAIL) {
+               page_counter_charge(&memcg->tcpmem, nr_pages);
+               return true;
+       }
+       return false;
+}
+
 static int __init memcg1_init(void)
 {
        int node;

diff --git a/mm/memcontrol-v1.h b/mm/memcontrol-v1.h
index ff972ec00eb31a843cd9a9379303cf56e79338c9..a5e35eb8374f546c15b7c138687ffb406bd9e836 100644 (file)
--- a/mm/memcontrol-v1.h
+++ b/mm/memcontrol-v1.h
@@ -103,6 +103,17 @@ void memcg1_check_events(struct mem_cgroup *memcg, int nid);
 void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
 
 void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages);
+static inline bool memcg1_tcpmem_active(struct mem_cgroup *memcg)
+{
+       return memcg->tcpmem_active;
+}
+bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+                        gfp_t gfp_mask);
+static inline void memcg1_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+       page_counter_uncharge(&memcg->tcpmem, nr_pages);
+}
+
 extern struct cftype memsw_files[];
 extern struct cftype mem_cgroup_legacy_files[];
 
@@ -122,6 +133,11 @@ static inline void memcg1_check_events(struct mem_cgroup *memcg, int nid) {}
 static inline void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) {}
 
 static inline void memcg1_account_kmem(struct mem_cgroup *memcg, int nr_pages) {}
+static inline bool memcg1_tcpmem_active(struct mem_cgroup *memcg) { return false; }
+static inline bool memcg1_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
+                                      gfp_t gfp_mask) { return true; }
+static inline void memcg1_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages) {}
+
 extern struct cftype memsw_files[];
 extern struct cftype mem_cgroup_legacy_files[];
 #endif /* CONFIG_MEMCG_V1 */

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 03d42b9356d11bf6dcfa9301adfe8531bccf69d3..8954e323cefb87283edc9adee4b78d5d4395681e 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3753,7 +3753,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_state *css)
        if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket)
                static_branch_dec(&memcg_sockets_enabled_key);
 
-       if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg->tcpmem_active)
+       if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && memcg1_tcpmem_active(memcg))
                static_branch_dec(&memcg_sockets_enabled_key);
 
 #if defined(CONFIG_MEMCG_KMEM)
@@ -4979,7 +4979,7 @@ void mem_cgroup_sk_alloc(struct sock *sk)
        memcg = mem_cgroup_from_task(current);
        if (mem_cgroup_is_root(memcg))
                goto out;
-       if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg->tcpmem_active)
+       if (!cgroup_subsys_on_dfl(memory_cgrp_subsys) && !memcg1_tcpmem_active(memcg))
                goto out;
        if (css_tryget(&memcg->css))
                sk->sk_memcg = memcg;
@@ -5005,20 +5005,8 @@ void mem_cgroup_sk_free(struct sock *sk)
 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
                             gfp_t gfp_mask)
 {
-       if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
-               struct page_counter *fail;
-
-               if (page_counter_try_charge(&memcg->tcpmem, nr_pages, &fail)) {
-                       memcg->tcpmem_pressure = 0;
-                       return true;
-               }
-               memcg->tcpmem_pressure = 1;
-               if (gfp_mask & __GFP_NOFAIL) {
-                       page_counter_charge(&memcg->tcpmem, nr_pages);
-                       return true;
-               }
-               return false;
-       }
+       if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
+               return memcg1_charge_skmem(memcg, nr_pages, gfp_mask);
 
        if (try_charge(memcg, gfp_mask, nr_pages) == 0) {
                mod_memcg_state(memcg, MEMCG_SOCK, nr_pages);
@@ -5036,7 +5024,7 @@ bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
        if (!cgroup_subsys_on_dfl(memory_cgrp_subsys)) {
-               page_counter_uncharge(&memcg->tcpmem, nr_pages);
+               memcg1_uncharge_skmem(memcg, nr_pages);
                return;
        }