[PATCH 2/3] mm: memcg: add per memcg "lru_gen" node

From: Huan Yang
Date: Sun Oct 08 2023 - 22:58:20 EST


From: HuanYang <link@xxxxxxxx>

This patch add "lru_gen" node in mem cgroup both in v1 and v2.

mem_cgroup_lru_gen_show just like global node, show lru_gen info,
but always show the full info due to per memcg no need to simple output.

Just like global node, per memcg "lru_gen" node can input cmd, but we
no need to type memcgid anymore to select one memcg.

Signed-off-by: HuanYang <link@xxxxxxxx>
---
include/linux/mmzone.h | 4 +-
mm/memcontrol.c | 163 +++++++++++++++++++++++++++++++++++++++++
mm/vmscan.c | 37 ++++++++++
3 files changed, 203 insertions(+), 1 deletion(-)

diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 4106fbc5b4b3..3d399ef177a4 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -553,7 +553,9 @@ void lru_gen_online_memcg(struct mem_cgroup *memcg);
void lru_gen_offline_memcg(struct mem_cgroup *memcg);
void lru_gen_release_memcg(struct mem_cgroup *memcg);
void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid);
-
+int mem_cgroup_lru_gen_cmd(char cmd, struct mem_cgroup *memcg, int nid,
+ unsigned long seq, int swappiness,
+ unsigned long opt);
#else /* !CONFIG_MEMCG */

#define MEMCG_NR_GENS 1
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ecc07b47e813..56385142c5b8 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5052,6 +5052,155 @@ static int mem_cgroup_slab_show(struct seq_file *m, void *p)

static int memory_stat_show(struct seq_file *m, void *v);

+#ifdef CONFIG_LRU_GEN
+static ssize_t mem_cgroup_lru_gen_write(struct kernfs_open_file *of, char *buf,
+ size_t nbytes, loff_t off)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
+ int n;
+ int end;
+ char cmd;
+ unsigned int nid;
+ unsigned long seq;
+ unsigned int swappiness = -1;
+ unsigned long opt = -1;
+ int ret;
+
+ buf = strstrip(buf);
+ n = sscanf(buf, "%c %u %lu %n %u %n %lu %n", &cmd, &nid, &seq, &end,
+ &swappiness, &end, &opt, &end);
+ if (n < 3 || buf[end])
+ return -EINVAL;
+
+ if (nid < 0 || nid >= MAX_NUMNODES || !node_state(nid, N_MEMORY))
+ return -EINVAL;
+
+ ret = mem_cgroup_lru_gen_cmd(cmd, memcg, nid, seq, swappiness, opt);
+ if (ret)
+ return ret;
+
+ return nbytes;
+}
+
+static void __lru_gen_show_info_full(struct seq_file *m, struct lruvec *lruvec,
+ unsigned long max_seq, unsigned long *min_seq,
+ unsigned long seq)
+{
+ int i;
+ int type, tier;
+ int hist = lru_hist_from_seq(seq);
+ struct lru_gen_folio *lrugen = &lruvec->lrugen;
+
+ for (tier = 0; tier < MAX_NR_TIERS; tier++) {
+ seq_printf(m, " %10d", tier);
+ for (type = 0; type < ANON_AND_FILE; type++) {
+ const char *s = " ";
+ unsigned long n[3] = {};
+
+ if (seq == max_seq) {
+ s = "RT ";
+ n[0] = READ_ONCE(lrugen->avg_refaulted[type][tier]);
+ n[1] = READ_ONCE(lrugen->avg_total[type][tier]);
+ } else if (seq == min_seq[type] || NR_HIST_GENS > 1) {
+ s = "rep";
+ n[0] = atomic_long_read(&lrugen->refaulted[hist][type][tier]);
+ n[1] = atomic_long_read(&lrugen->evicted[hist][type][tier]);
+ if (tier)
+ n[2] = READ_ONCE(lrugen->protected[hist][type][tier - 1]);
+ }
+
+ for (i = 0; i < 3; i++)
+ seq_printf(m, " %10lu%c", n[i], s[i]);
+ }
+ seq_putc(m, '\n');
+ }
+
+ seq_puts(m, " ");
+ for (i = 0; i < NR_MM_STATS; i++) {
+ const char *s = " ";
+ unsigned long n = 0;
+
+ if (seq == max_seq && NR_HIST_GENS == 1) {
+ s = "LOYNFA";
+ n = READ_ONCE(lruvec->mm_state.stats[hist][i]);
+ } else if (seq != max_seq && NR_HIST_GENS > 1) {
+ s = "loynfa";
+ n = READ_ONCE(lruvec->mm_state.stats[hist][i]);
+ }
+
+ seq_printf(m, " %10lu%c", n, s[i]);
+ }
+ seq_putc(m, '\n');
+}
+
+
+static int __lru_gen_show_info(struct seq_file *m, struct mem_cgroup *memcg, int nid)
+{
+ unsigned long seq;
+ struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(nid));
+ struct lru_gen_folio *lrugen = &lruvec->lrugen;
+ DEFINE_MAX_SEQ(lruvec);
+ DEFINE_MIN_SEQ(lruvec);
+ char *path = kvmalloc(PATH_MAX, GFP_KERNEL);
+
+ if (unlikely(!path))
+ return -ENOMEM;
+
+ if (nid == first_memory_node) {
+ cgroup_path(memcg->css.cgroup, path, PATH_MAX);
+ seq_printf(m, "memcg %5u %s\n", mem_cgroup_id(memcg), path);
+ }
+
+ seq_printf(m, " node %5d\n", nid);
+
+ if (max_seq >= MAX_NR_GENS)
+ seq = max_seq - MAX_NR_GENS + 1;
+ else
+ seq = 0;
+
+ for (; seq <= max_seq; seq++) {
+ int type, zone;
+ int gen = lru_gen_from_seq(seq);
+ unsigned long birth = READ_ONCE(lrugen->timestamps[gen]);
+
+ seq_printf(m, " %10lu %10u", seq, jiffies_to_msecs(jiffies - birth));
+
+ for (type = 0; type < ANON_AND_FILE; type++) {
+ unsigned long size = 0;
+ char mark = seq < min_seq[type] ? 'x' : ' ';
+
+ for (zone = 0; zone < MAX_NR_ZONES; zone++)
+ size += max(READ_ONCE(lrugen->nr_pages[gen][type][zone]), 0L);
+
+ seq_printf(m, " %10lu%c", size, mark);
+ }
+
+ seq_putc(m, '\n');
+
+
+ __lru_gen_show_info_full(m, lruvec, max_seq, min_seq, seq);
+ }
+
+ kvfree(path);
+
+ return 0;
+}
+
+static int mem_cgroup_lru_gen_show(struct seq_file *m, void *v)
+{
+ int nid, ret;
+ struct mem_cgroup *memcg = mem_cgroup_from_seq(m);
+
+ for_each_node_state(nid, N_MEMORY) {
+ ret = __lru_gen_show_info(m, memcg, nid);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
static struct cftype mem_cgroup_legacy_files[] = {
{
.name = "usage_in_bytes",
@@ -5172,6 +5321,13 @@ static struct cftype mem_cgroup_legacy_files[] = {
.write = mem_cgroup_reset,
.read_u64 = mem_cgroup_read_u64,
},
+#ifdef CONFIG_LRU_GEN
+ {
+ .name = "lru_gen",
+ .write = mem_cgroup_lru_gen_write,
+ .seq_show = mem_cgroup_lru_gen_show,
+ },
+#endif
{ }, /* terminate */
};

@@ -6831,6 +6987,13 @@ static struct cftype memory_files[] = {
.flags = CFTYPE_NS_DELEGATABLE,
.write = memory_reclaim,
},
+#ifdef CONFIG_LRU_GEN
+ {
+ .name = "lru_gen",
+ .write = mem_cgroup_lru_gen_write,
+ .seq_show = mem_cgroup_lru_gen_show,
+ },
+#endif
{ } /* terminate */
};

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f59977964e81..4da200cda0b9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -6072,6 +6072,43 @@ static int __process_one_cmd(char cmd, struct lruvec *lruvec, unsigned long seq,
return err;
}

+#ifdef CONFIG_MEMCG
+int mem_cgroup_lru_gen_cmd(char cmd, struct mem_cgroup *memcg, int nid,
+ unsigned long seq, int swappiness, unsigned long opt)
+{
+ int err;
+ struct lruvec *lruvec;
+ unsigned int flags;
+ struct blk_plug plug;
+ struct scan_control sc = {
+ .may_writepage = true,
+ .may_unmap = true,
+ .may_swap = true,
+ .reclaim_idx = MAX_NR_ZONES - 1,
+ .gfp_mask = GFP_KERNEL,
+ };
+
+ set_task_reclaim_state(current, &sc.reclaim_state);
+ flags = memalloc_noreclaim_save();
+ blk_start_plug(&plug);
+ if (!set_mm_walk(NULL, true)) {
+ err = -ENOMEM;
+ goto done;
+ }
+
+ lruvec = get_lruvec(memcg, nid);
+ err = __process_one_cmd(cmd, lruvec, seq, &sc, swappiness, opt);
+
+done:
+ clear_mm_walk();
+ blk_finish_plug(&plug);
+ memalloc_noreclaim_restore(flags);
+ set_task_reclaim_state(current, NULL);
+
+ return err;
+}
+#endif
+
static int run_cmd(char cmd, int memcg_id, int nid, unsigned long seq,
struct scan_control *sc, int swappiness, unsigned long opt)
{
--
2.34.1