[PATCH RFC 2/3] mm: memcontrol: record driver memory statistics

[Qiang Yu <qiang.yu@xxxxxxx>]

Signed-off-by: Qiang Yu <qiang.yu@xxxxxxx>
---
 include/linux/memcontrol.h | 1 +
 mm/memcontrol.c            | 9 +++++++++
 2 files changed, 10 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d76977943265..6518b4b5ee07 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -36,6 +36,7 @@ enum memcg_stat_item {
 	MEMCG_SOCK,
 	/* XXX: why are these zone and not node counters? */
 	MEMCG_KERNEL_STACK_KB,
+	MEMCG_DRV,
 	MEMCG_NR_STAT,
 };
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 28595c276e6b..cdd3f3401598 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1413,6 +1413,9 @@ static char *memory_stat_format(struct mem_cgroup *memcg)
 	seq_buf_printf(&s, "sock %llu\n",
 		       (u64)memcg_page_state(memcg, MEMCG_SOCK) *
 		       PAGE_SIZE);
+	seq_buf_printf(&s, "driver %llu\n",
+		       (u64)memcg_page_state(memcg, MEMCG_DRV) *
+		       PAGE_SIZE);
 
 	seq_buf_printf(&s, "shmem %llu\n",
 		       (u64)memcg_page_state(memcg, NR_SHMEM) *
@@ -6947,6 +6950,9 @@ EXPORT_SYMBOL(mem_cgroup_driver_get_from_current);
 int mem_cgroup_charge_drvmem(struct mem_cgroup *memcg, gfp_t gfp,
 			     unsigned long nr_pages)
 {
+	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+		mod_memcg_state(memcg, MEMCG_DRV, nr_pages);
+
 	return try_charge(memcg, gfp, nr_pages);
 }
 EXPORT_SYMBOL(mem_cgroup_charge_drvmem);
@@ -6958,6 +6964,9 @@ EXPORT_SYMBOL(mem_cgroup_charge_drvmem);
  */
 void mem_cgroup_uncharge_drvmem(struct mem_cgroup *memcg, unsigned long nr_pages)
 {
+	if (cgroup_subsys_on_dfl(memory_cgrp_subsys))
+		mod_memcg_state(memcg, MEMCG_DRV, -nr_pages);
+
 	refill_stock(memcg, nr_pages);
 }
 EXPORT_SYMBOL(mem_cgroup_uncharge_drvmem);
-- 
2.17.1