mm: memcg: add per-memcg zswap writeback stat

Since zswap now writes back pages from memcg-specific LRUs, we now need a
new stat to show writebacks count for each memcg.

[nphamcs@gmail.com: rename ZSWP_WB to ZSWPWB]
Link: https://lkml.kernel.org/r/20231205193307.2432803-1-nphamcs@gmail.com
Link: https://lkml.kernel.org/r/20231130194023.4102148-5-nphamcs@gmail.com
Suggested-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Yosry Ahmed <yosryahmed@google.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/vm_event_item.h b/include/linux/vm_event_item.h
index d1b847502f09cb517b7eab0c19a2589f776b538d..747943bc8cc2deda8bb5a79f4c0bd6b4fa027868 100644 (file)
--- a/include/linux/vm_event_item.h
+++ b/include/linux/vm_event_item.h
@@ -142,6 +142,7 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
 #ifdef CONFIG_ZSWAP
                ZSWPIN,
                ZSWPOUT,
+               ZSWPWB,
 #endif
 #ifdef CONFIG_X86
                DIRECT_MAP_LEVEL2_SPLIT,

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ce75e504fe8b4918595976e09c212a929eee3434..69b0ad45524257a36a1516ffc589d55d53569d8c 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -703,6 +703,7 @@ static const unsigned int memcg_vm_event_stat[] = {
 #if defined(CONFIG_MEMCG_KMEM) && defined(CONFIG_ZSWAP)
        ZSWPIN,
        ZSWPOUT,
+       ZSWPWB,
 #endif
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
        THP_FAULT_ALLOC,

diff --git a/mm/vmstat.c b/mm/vmstat.c
index afa5a38fcc9c90a51c834ec6a93da65fdfe06aa5..cfd8d8256f8eaee68e69015423d3269a1543dbff 100644 (file)
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -1401,6 +1401,7 @@ const char * const vmstat_text[] = {
 #ifdef CONFIG_ZSWAP
        "zswpin",
        "zswpout",
+       "zswpwb",
 #endif
 #ifdef CONFIG_X86
        "direct_map_level2_splits",

diff --git a/mm/zswap.c b/mm/zswap.c
index 213626e0f659c99b6b5589f5e8fdff73eafd798e..c329fca810c84c8d19340648e662ed5eff2b524e 100644 (file)
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -760,6 +760,10 @@ static enum lru_status shrink_memcg_cb(struct list_head *item, struct list_lru_o
        }
        zswap_written_back_pages++;
 
+       if (entry->objcg)
+               count_objcg_event(entry->objcg, ZSWPWB);
+
+       count_vm_event(ZSWPWB);
        /*
         * Writeback started successfully, the page now belongs to the
         * swapcache. Drop the entry from zswap - unless invalidate already