[Devel] [PATCH RHEL COMMIT] mm: memcontrol: add stats for reclaimable and unreclaimable stats

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.vz9.1.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after ark-5.14
------>
commit e7d2cdabedc71916b7ca50aaf28d0ea6353af71d
Author: Vladimir Davydov <vdavydov.dev at gmail.com>
Date:   Thu Sep 30 17:44:01 2021 +0300

    mm: memcontrol: add stats for reclaimable and unreclaimable stats
    
    Required by vcmmd for estimating the size of available memory, which in
    turn is used for calculating the lower boundary for memory limit.
    
    Also, these counters will be used by the following patches.
    
    Signed-off-by: Vladimir Davydov <vdavydov at virtuozzo.com>
    Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
    
    +++
    memcg: Show correct values of slab_[un]reclaimable in memory.stat files
    
    The values of NR_SLAB_RECLAIMABLE_B and NR_SLAB_UNRECLAIMABLE_B counters
    are in bytes rather than in pages. So, one should not multiply them by
    PAGE_SIZE when preparing the records for 'memory.stat' files in the memory
    cgroups.
    
    This also applies to 'total_slab_[un]reclaimable' stats in those files.
    
    https://jira.sw.ru/browse/PSBM-132728
    
    Signed-off-by: Evgenii Shatokhin <eshatokhin at virtuozzo.com>
    
    Cherry-picked from vz8 commit 6ee44bfbd469 ("mm: memcontrol: add stats
    for reclaimable and unreclaimable stats")).
    
    Applied cosmetic fixes: remove unneeded cast, make type of 'nr' same
    in both loops inside memcg_stat_show().
    
    Signed-off-by: Nikita Yushchenko <nikita.yushchenko at virtuozzo.com>
---
 mm/memcontrol.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d51f09a70bcd..c2b527cf73dc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4076,6 +4076,8 @@ static const unsigned int memcg1_stats[] = {
 	NR_FILE_MAPPED,
 	NR_FILE_DIRTY,
 	NR_WRITEBACK,
+	NR_SLAB_RECLAIMABLE_B,
+	NR_SLAB_UNRECLAIMABLE_B,
 	MEMCG_SWAP,
 };
 
@@ -4089,6 +4091,8 @@ static const char *const memcg1_stat_names[] = {
 	"mapped_file",
 	"dirty",
 	"writeback",
+	"slab_reclaimable",
+	"slab_unreclaimable",
 	"swap",
 };
 
@@ -4112,12 +4116,14 @@ static int memcg_stat_show(struct seq_file *m, void *v)
 	cgroup_rstat_flush(memcg->css.cgroup);
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
-		unsigned long nr;
+		u64 nr;
 
 		if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
 			continue;
 		nr = memcg_page_state_local(memcg, memcg1_stats[i]);
-		seq_printf(m, "%s %lu\n", memcg1_stat_names[i], nr * PAGE_SIZE);
+		if (!vmstat_item_in_bytes(memcg1_stats[i]))
+			nr *= PAGE_SIZE;
+		seq_printf(m, "%s %llu\n", memcg1_stat_names[i], nr);
 	}
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)
@@ -4142,13 +4148,14 @@ static int memcg_stat_show(struct seq_file *m, void *v)
 			   (u64)memsw * PAGE_SIZE);
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_stats); i++) {
-		unsigned long nr;
+		u64 nr;
 
 		if (memcg1_stats[i] == MEMCG_SWAP && !do_memsw_account())
 			continue;
 		nr = memcg_page_state(memcg, memcg1_stats[i]);
-		seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i],
-						(u64)nr * PAGE_SIZE);
+		if (!vmstat_item_in_bytes(memcg1_stats[i]))
+			nr *= PAGE_SIZE;
+		seq_printf(m, "total_%s %llu\n", memcg1_stat_names[i], nr);
 	}
 
 	for (i = 0; i < ARRAY_SIZE(memcg1_events); i++)