[PATCH v2] Port hierarchical_{memory,swap}_limit cgroup1->cgroup2

["Jan Kratochvil (Azul)" <jkratochvil@azul.com>]

Hello Waiman,

On Fri, 09 Feb 2024 23:51:54 +0800, Waiman Long wrote:
> I don't think we use mi->memsw in cgroup v2, only memory and swap should
> be used.

you are right, thanks:

struct mem_cgroup {
...
	union {
		struct page_counter swap;       /* v2 only */
		struct page_counter memsw;      /* v1 only */
	};


Jan Kratochvil


Signed-off-by: Jan Kratochvil (Azul) <jkratochvil@azul.com>

 mm/memcontrol.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 46d8d0211..2631dd810 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1636,6 +1636,8 @@ static inline unsigned long memcg_page_state_local_output(
 static void memcg_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
 {
 	int i;
+	unsigned long memory, swap;
+	struct mem_cgroup *mi;
 
 	/*
 	 * Provide statistics on the state of the memory subsystem as
@@ -1682,6 +1684,17 @@ static void memcg_stat_format(struct mem_cgroup *memcg, struct seq_buf *s)
 			       memcg_events(memcg, memcg_vm_event_stat[i]));
 	}
 
+	/* Hierarchical information */
+	memory = swap = PAGE_COUNTER_MAX;
+	for (mi = memcg; mi; mi = parent_mem_cgroup(mi)) {
+		memory = min(memory, READ_ONCE(mi->memory.max));
+		swap = min(swap, READ_ONCE(mi->swap.max));
+	}
+	seq_buf_printf(s, "hierarchical_memory_limit %llu\n",
+		       (u64)memory * PAGE_SIZE);
+	seq_buf_printf(s, "hierarchical_swap_limit %llu\n",
+		       (u64)swap * PAGE_SIZE);
+
 	/* The above should easily fit into one page */
 	WARN_ON_ONCE(seq_buf_has_overflowed(s));
 }