page_counter-track-failcnt-only-for-legacy-cgroups.patch removed from -mm tree

@@ -28,12 +28,13 @@ struct page_counter {
 	unsigned long watermark;
 	/* Latest cg2 reset watermark */
 	unsigned long local_watermark;
-	unsigned long failcnt;
+	unsigned long failcnt; /* v1-only field */
 
 	/* Keep all the read most fields in a separete cacheline. */
 	CACHELINE_PADDING(_pad2_);
 
 	bool protection_support;
+	bool track_failcnt;
 	unsigned long min;
 	unsigned long low;
 	unsigned long high;

@@ -58,6 +59,7 @@ static inline void page_counter_init(str
 	counter->max = PAGE_COUNTER_MAX;
 	counter->parent = parent;
 	counter->protection_support = protection_support;
+	counter->track_failcnt = false;
 }
 
 static inline unsigned long page_counter_read(struct page_counter *counter)

@@ -101,10 +101,9 @@ static void hugetlb_cgroup_init(struct h
 	int idx;
 
 	for (idx = 0; idx < HUGE_MAX_HSTATE; idx++) {
-		struct page_counter *fault_parent = NULL;
-		struct page_counter *rsvd_parent = NULL;
+		struct page_counter *fault, *fault_parent = NULL;
+		struct page_counter *rsvd, *rsvd_parent = NULL;
 		unsigned long limit;
-		int ret;
 
 		if (parent_h_cgroup) {
 			fault_parent = hugetlb_cgroup_counter_from_cgroup(

@@ -112,24 +111,22 @@ static void hugetlb_cgroup_init(struct h
 			rsvd_parent = hugetlb_cgroup_counter_from_cgroup_rsvd(
 				parent_h_cgroup, idx);
 		}
-		page_counter_init(hugetlb_cgroup_counter_from_cgroup(h_cgroup,
-								     idx),
-				  fault_parent, false);
-		page_counter_init(
-			hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
-			rsvd_parent, false);
+		fault = hugetlb_cgroup_counter_from_cgroup(h_cgroup, idx);
+		rsvd = hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx);
+
+		page_counter_init(fault, fault_parent, false);
+		page_counter_init(rsvd, rsvd_parent, false);
+
+		if (!cgroup_subsys_on_dfl(hugetlb_cgrp_subsys)) {
+			fault->track_failcnt = true;
+			rsvd->track_failcnt = true;
+		}
 
 		limit = round_down(PAGE_COUNTER_MAX,
 				   pages_per_huge_page(&hstates[idx]));
 
-		ret = page_counter_set_max(
-			hugetlb_cgroup_counter_from_cgroup(h_cgroup, idx),
-			limit);
-		VM_BUG_ON(ret);
-		ret = page_counter_set_max(
-			hugetlb_cgroup_counter_from_cgroup_rsvd(h_cgroup, idx),
-			limit);
-		VM_BUG_ON(ret);
+		VM_BUG_ON(page_counter_set_max(fault, limit));
+		VM_BUG_ON(page_counter_set_max(rsvd, limit));
 	}
 }
 

@@ -1572,16 +1572,23 @@ void mem_cgroup_print_oom_meminfo(struct
 	/* Use static buffer, for the caller is holding oom_lock. */
 	static char buf[SEQ_BUF_SIZE];
 	struct seq_buf s;
+	unsigned long memory_failcnt;
 
 	lockdep_assert_held(&oom_lock);
 
+	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+		memory_failcnt = atomic_long_read(&memcg->memory_events[MEMCG_MAX]);
+	else
+		memory_failcnt = memcg->memory.failcnt;
+
 	pr_info("memory: usage %llukB, limit %llukB, failcnt %lu\n",
 		K((u64)page_counter_read(&memcg->memory)),
-		K((u64)READ_ONCE(memcg->memory.max)), memcg->memory.failcnt);
+		K((u64)READ_ONCE(memcg->memory.max)), memory_failcnt);
 	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
 		pr_info("swap: usage %llukB, limit %llukB, failcnt %lu\n",
 			K((u64)page_counter_read(&memcg->swap)),
-			K((u64)READ_ONCE(memcg->swap.max)), memcg->swap.failcnt);
+			K((u64)READ_ONCE(memcg->swap.max)),
+			atomic_long_read(&memcg->memory_events[MEMCG_SWAP_MAX]));
 #ifdef CONFIG_MEMCG_V1
 	else {
 		pr_info("memory+swap: usage %llukB, limit %llukB, failcnt %lu\n",

@@ -3631,6 +3638,7 @@ mem_cgroup_css_alloc(struct cgroup_subsy
 		page_counter_init(&memcg->memory, &parent->memory, memcg_on_dfl);
 		page_counter_init(&memcg->swap, &parent->swap, false);
 #ifdef CONFIG_MEMCG_V1
+		memcg->memory.track_failcnt = !memcg_on_dfl;
 		WRITE_ONCE(memcg->oom_kill_disable, READ_ONCE(parent->oom_kill_disable));
 		page_counter_init(&memcg->kmem, &parent->kmem, false);
 		page_counter_init(&memcg->tcpmem, &parent->tcpmem, false);

@@ -121,6 +121,7 @@ bool page_counter_try_charge(struct page
 {
 	struct page_counter *c;
 	bool protection = track_protection(counter);
+	bool track_failcnt = counter->track_failcnt;
 
 	for (c = counter; c; c = c->parent) {
 		long new;

@@ -146,7 +147,8 @@ bool page_counter_try_charge(struct page
 			 * inaccuracy in the failcnt which is only used
 			 * to report stats.
 			 */
-			data_race(c->failcnt++);
+			if (track_failcnt)
+				data_race(c->failcnt++);
 			*fail = c;
 			goto failed;
 		}