memcg: cgroup: call css_rstat_updated irrespective of in_nmi()

css_rstat_updated() is nmi safe, so there is no need to avoid it in
in_nmi(), so remove the check.

Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Tested-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: shakeelb

mm/memcontrol.c

@@ -573,9 +573,7 @@ static inline void memcg_rstat_updated(struct mem_cgroup *memcg, int val,
 	if (!val)
 		return;
 
-	/* TODO: add to cgroup update tree once it is nmi-safe. */
-	if (!in_nmi())
-		css_rstat_updated(&memcg->css, cpu);
+	css_rstat_updated(&memcg->css, cpu);
 	statc_pcpu = memcg->vmstats_percpu;
 	for (; statc_pcpu; statc_pcpu = statc->parent_pcpu) {
 		statc = this_cpu_ptr(statc_pcpu);
@@ -2530,7 +2528,8 @@ static inline void account_slab_nmi_safe(struct mem_cgroup *memcg,
 	} else {
 		struct mem_cgroup_per_node *pn = memcg->nodeinfo[pgdat->node_id];
 
-		/* TODO: add to cgroup update tree once it is nmi-safe. */
+		/* preemption is disabled in_nmi(). */
+		css_rstat_updated(&memcg->css, smp_processor_id());
 		if (idx == NR_SLAB_RECLAIMABLE_B)
 			atomic_add(nr, &pn->slab_reclaimable);
 		else
@@ -2753,7 +2752,8 @@ 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. */
+		/* preemption is disabled in_nmi(). */
+		css_rstat_updated(&memcg->css, smp_processor_id());
 		atomic_add(val, &memcg->kmem_stat);
 	}
 }