@@ -2691,6 +2691,20 @@ void __memcg_kmem_uncharge_page(struct page *page, int order)
obj_cgroup_put(objcg);
}
+/* Replace the stock objcg with objcg, return the old objcg */
+static struct obj_cgroup *replace_stock_objcg(struct memcg_stock_pcp *stock,
+ struct obj_cgroup *objcg)
+{
+ struct obj_cgroup *old = NULL;
+
+ old = drain_obj_stock(stock);
+ obj_cgroup_get(objcg);
+ stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
+ ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
+ WRITE_ONCE(stock->cached_objcg, objcg);
+ return old;
+}
+
static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
enum node_stat_item idx, int nr)
{
@@ -2708,11 +2722,7 @@ static void mod_objcg_state(struct obj_cgroup *objcg, struct pglist_data *pgdat,
* changes.
*/
if (READ_ONCE(stock->cached_objcg) != objcg) {
- old = drain_obj_stock(stock);
- obj_cgroup_get(objcg);
- stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
- ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
- WRITE_ONCE(stock->cached_objcg, objcg);
+ old = replace_stock_objcg(stock, objcg);
stock->cached_pgdat = pgdat;
} else if (stock->cached_pgdat != pgdat) {
/* Flush the existing cached vmstat data */
@@ -2866,11 +2876,7 @@ static void refill_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes,
stock = this_cpu_ptr(&memcg_stock);
if (READ_ONCE(stock->cached_objcg) != objcg) { /* reset if necessary */
- old = drain_obj_stock(stock);
- obj_cgroup_get(objcg);
- WRITE_ONCE(stock->cached_objcg, objcg);
- stock->nr_bytes = atomic_read(&objcg->nr_charged_bytes)
- ? atomic_xchg(&objcg->nr_charged_bytes, 0) : 0;
+ old = replace_stock_objcg(stock, objcg);
allow_uncharge = true; /* Allow uncharge when objcg changes */
}
stock->nr_bytes += nr_bytes;