mm: change count_objcg_event() to count_objcg_events() for batch event updates

With the introduction of zswap_store() swapping out large folios, we need
to efficiently update the objcg's memcg events once per successfully
stored folio.  For instance, the 'ZSWPOUT' event needs to be incremented
by folio_nr_pages().

To facilitate this, the existing count_objcg_event() API is modified to be
count_objcg_events() that additionally accepts a count parameter.  The
only existing calls to count_objcg_event() are in zswap.c - these have
been modified to call count_objcg_events() with a count of 1.

Link: https://lkml.kernel.org/r/20241001053222.6944-5-kanchana.p.sridhar@intel.com
Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Wajdi Feghali <wajdi.k.feghali@intel.com>
Cc: "Zou, Nanhai" <nanhai.zou@intel.com>
Cc: Barry Song <21cnbao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 15c2716f9aa320a7747e443f5e2ec9f56b500544..524006313b0d350d58544181188ba3d88ecf52e9 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1764,8 +1764,9 @@ static inline int memcg_kmem_id(struct mem_cgroup *memcg)
 
 struct mem_cgroup *mem_cgroup_from_slab_obj(void *p);
 
-static inline void count_objcg_event(struct obj_cgroup *objcg,
-                                    enum vm_event_item idx)
+static inline void count_objcg_events(struct obj_cgroup *objcg,
+                                     enum vm_event_item idx,
+                                     unsigned long count)
 {
        struct mem_cgroup *memcg;
 
@@ -1774,7 +1775,7 @@ static inline void count_objcg_event(struct obj_cgroup *objcg,
 
        rcu_read_lock();
        memcg = obj_cgroup_memcg(objcg);
-       count_memcg_events(memcg, idx, 1);
+       count_memcg_events(memcg, idx, count);
        rcu_read_unlock();
 }
 
@@ -1829,8 +1830,9 @@ static inline struct mem_cgroup *mem_cgroup_from_slab_obj(void *p)
        return NULL;
 }
 
-static inline void count_objcg_event(struct obj_cgroup *objcg,
-                                    enum vm_event_item idx)
+static inline void count_objcg_events(struct obj_cgroup *objcg,
+                                     enum vm_event_item idx,
+                                     unsigned long count)
 {
 }
 

diff --git a/mm/zswap.c b/mm/zswap.c
index d6f023a320504310d84613582a5b9e442672a828..f8a39f675a6006d9e121e93226fc9b4313b32fce 100644 (file)
--- a/mm/zswap.c
+++ b/mm/zswap.c
@@ -1052,7 +1052,7 @@ static int zswap_writeback_entry(struct zswap_entry *entry,
 
        count_vm_event(ZSWPWB);
        if (entry->objcg)
-               count_objcg_event(entry->objcg, ZSWPWB);
+               count_objcg_events(entry->objcg, ZSWPWB, 1);
 
        zswap_entry_free(entry);
 
@@ -1481,7 +1481,7 @@ bool zswap_store(struct folio *folio)
 
        if (objcg) {
                obj_cgroup_charge_zswap(objcg, entry->length);
-               count_objcg_event(objcg, ZSWPOUT);
+               count_objcg_events(objcg, ZSWPOUT, 1);
        }
 
        /*
@@ -1575,7 +1575,7 @@ bool zswap_load(struct folio *folio)
 
        count_vm_event(ZSWPIN);
        if (entry->objcg)
-               count_objcg_event(entry->objcg, ZSWPIN);
+               count_objcg_events(entry->objcg, ZSWPIN, 1);
 
        if (swapcache) {
                zswap_entry_free(entry);