Merge tag 'cgroup-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:

 - Allow css_rstat_updated() in NMI context to enable memory accounting
   for allocations in NMI context.

 - /proc/cgroups doesn't contain useful information for cgroup2 and was
   updated to only show v1 controllers. This unfortunately broke
   something in the wild. Add an option to bring back the old behavior
   to ease transition.

 - selftest updates and other cleanups.

* tag 'cgroup-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Add compatibility option for content of /proc/cgroups
  selftests/cgroup: fix cpu.max tests
  cgroup: llist: avoid memory tears for llist_node
  selftests: cgroup: Fix missing newline in test_zswap_writeback_one
  selftests: cgroup: Allow longer timeout for kmem_dead_cgroups cleanup
  memcg: cgroup: call css_rstat_updated irrespective of in_nmi()
  cgroup: remove per-cpu per-subsystem locks
  cgroup: make css_rstat_updated nmi safe
  cgroup: support to enable nmi-safe css_rstat_updated
  selftests: cgroup: Fix compilation on pre-cgroupns kernels
  selftests: cgroup: Optionally set up v1 environment
  selftests: cgroup: Add support for named v1 hierarchies in test_core
  selftests: cgroup_util: Add helpers for testing named v1 hierarchies
  Documentation: cgroup: add section explaining controller availability
  cgroup: Drop sock_cgroup_classid() dummy implementation

1 files changed, 5 insertions, 5 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index de7d737fe011..8dd7fbed5a94 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -570,9 +570,7 @@ 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);
@@ -2527,7 +2525,8 @@ 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
@@ -2750,7 +2749,8 @@ 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);
 	}
 }