[PATCH 4/7] memcg: add hooks for gpu memcg charging/uncharging.

[Dave Airlie <airlied@gmail.com>]

From: Dave Airlie <airlied@redhat.com>

As per the socket hooks, just adds two APIs to charge GPU pages
to the memcg and uncharge them.

Suggested by Waiman.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 include/linux/memcontrol.h |  5 +++++
 mm/memcontrol.c            | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 4058d4bd94ed..f74b7db89f00 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1618,6 +1618,11 @@ struct sock;
 bool mem_cgroup_charge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages,
 			     gfp_t gfp_mask);
 void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages);
+
+bool mem_cgroup_charge_gpu(struct mem_cgroup *memcg, unsigned int nr_pages,
+			   gfp_t gfp_mask);
+void mem_cgroup_uncharge_gpu(struct mem_cgroup *memcg, unsigned int nr_pages);
+
 #ifdef CONFIG_MEMCG
 extern struct static_key_false memcg_sockets_enabled_key;
 #define mem_cgroup_sockets_enabled static_branch_unlikely(&memcg_sockets_enabled_key)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 25471a0fd0be..76a0ec34b7dc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4958,6 +4958,40 @@ void mem_cgroup_uncharge_skmem(struct mem_cgroup *memcg, unsigned int nr_pages)
 	refill_stock(memcg, nr_pages);
 }
 
+/**
+ * mem_cgroup_charge_gpu - charge GPU memory
+ * @memcg: memcg to charge
+ * @nr_pages: number of pages to charge
+ * @gfp_mask: reclaim mode
+ *
+ * Charges @nr_pages to @memcg. Returns %true if the charge fit within
+ * @memcg's configured limit, %false if it doesn't.
+ */
+bool mem_cgroup_charge_gpu(struct mem_cgroup *memcg, unsigned int nr_pages,
+			   gfp_t gfp_mask)
+{
+	if (try_charge_memcg(memcg, gfp_mask, nr_pages) == 0) {
+		mod_memcg_state(memcg, MEMCG_GPU, nr_pages);
+		return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(mem_cgroup_charge_gpu);
+
+/**
+ * mem_cgroup_uncharge_gpu - uncharge GPU memory
+ * @memcg: memcg to uncharge
+ * @nr_pages: number of pages to uncharge
+ */
+void mem_cgroup_uncharge_gpu(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+	mod_memcg_state(memcg, MEMCG_GPU, -nr_pages);
+
+	refill_stock(memcg, nr_pages);
+}
+EXPORT_SYMBOL_GPL(mem_cgroup_uncharge_gpu);
+
 static int __init cgroup_memory(char *s)
 {
 	char *token;
-- 
2.49.0