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authorShakeel Butt <shakeel.butt@linux.dev>2025-05-18 23:31:40 -0700
committerAndrew Morton <akpm@linux-foundation.org>2025-05-31 22:46:09 -0700
commit9d3edf96cef6d65ca2be287e48d40aec90081f3f (patch)
tree80bc09135501d923f2ff1dbef61de71568721e43 /mm
parentmemcg: nmi safe memcg stats for specific archs (diff)
downloadlinux-rng-9d3edf96cef6d65ca2be287e48d40aec90081f3f.tar.xz
linux-rng-9d3edf96cef6d65ca2be287e48d40aec90081f3f.zip
memcg: add nmi-safe update for MEMCG_KMEM
The objcg based kmem charging and uncharging code path needs to update MEMCG_KMEM appropriately. Let's add support to update MEMCG_KMEM in nmi-safe way for those code paths. Link: https://lkml.kernel.org/r/20250519063142.111219-4-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memcontrol.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index e8e8becbe926..74bb19fcafad 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2715,6 +2715,23 @@ struct obj_cgroup *get_obj_cgroup_from_folio(struct folio *folio)
return objcg;
}
+#ifdef CONFIG_MEMCG_NMI_SAFETY_REQUIRES_ATOMIC
+static inline void account_kmem_nmi_safe(struct mem_cgroup *memcg, int val)
+{
+ if (likely(!in_nmi())) {
+ mod_memcg_state(memcg, MEMCG_KMEM, val);
+ } else {
+ /* TODO: add to cgroup update tree once it is nmi-safe. */
+ atomic_add(val, &memcg->kmem_stat);
+ }
+}
+#else
+static inline void account_kmem_nmi_safe(struct mem_cgroup *memcg, int val)
+{
+ mod_memcg_state(memcg, MEMCG_KMEM, val);
+}
+#endif
+
/*
* obj_cgroup_uncharge_pages: uncharge a number of kernel pages from a objcg
* @objcg: object cgroup to uncharge
@@ -2727,7 +2744,7 @@ static void obj_cgroup_uncharge_pages(struct obj_cgroup *objcg,
memcg = get_mem_cgroup_from_objcg(objcg);
- mod_memcg_state(memcg, MEMCG_KMEM, -nr_pages);
+ account_kmem_nmi_safe(memcg, -nr_pages);
memcg1_account_kmem(memcg, -nr_pages);
if (!mem_cgroup_is_root(memcg))
refill_stock(memcg, nr_pages);
@@ -2755,7 +2772,7 @@ static int obj_cgroup_charge_pages(struct obj_cgroup *objcg, gfp_t gfp,
if (ret)
goto out;
- mod_memcg_state(memcg, MEMCG_KMEM, nr_pages);
+ account_kmem_nmi_safe(memcg, nr_pages);
memcg1_account_kmem(memcg, nr_pages);
out:
css_put(&memcg->css);