From 8881f7e6d38a23ffadea17c14025e52646af37ce Mon Sep 17 00:00:00 2001
From: Johannes Weiner <hannes@cmpxchg.org>
Date: Thu, 17 Feb 2022 10:48:01 +0100
Subject: [PATCH] mm/memcg: Opencode the inner part of
obj_cgroup_uncharge_pages() in drain_obj_stock()
References: SLE Realtime Extension
Patch-mainline: v5.18-rc1
Git-commit: af9a3b69e84bef996ce4620282fcf69a5786be3a
Provide the inner part of refill_stock() as __refill_stock() without
disabling interrupts. This eases the integration of local_lock_t where
recursive locking must be avoided.
Open code obj_cgroup_uncharge_pages() in drain_obj_stock() and use
__refill_stock(). The caller of drain_obj_stock() already disables
interrupts.
[bigeasy: Patch body around Johannes' diff ]
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
mm/memcontrol.c | 26 ++++++++++++++++++++------
1 file changed, 20 insertions(+), 6 deletions(-)
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 0ba33ef0e365..eca22c3099cc 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2230,12 +2230,9 @@ static void drain_local_stock(struct work_struct *dummy)
* Cache charges(val) to local per_cpu area.
* This will be consumed by consume_stock() function, later.
*/
-static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
+static void __refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
{
struct memcg_stock_pcp *stock;
- unsigned long flags;
-
- local_irq_save(flags);
stock = this_cpu_ptr(&memcg_stock);
if (stock->cached != memcg) { /* reset if necessary */
@@ -2247,7 +2244,14 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
if (stock->nr_pages > MEMCG_CHARGE_BATCH)
drain_stock(stock);
+}
+static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ __refill_stock(memcg, nr_pages);
local_irq_restore(flags);
}
@@ -3173,8 +3177,18 @@ static void drain_obj_stock(struct memcg_stock_pcp *stock)
unsigned int nr_pages = stock->nr_bytes >> PAGE_SHIFT;
unsigned int nr_bytes = stock->nr_bytes & (PAGE_SIZE - 1);
- if (nr_pages)
- obj_cgroup_uncharge_pages(old, nr_pages);
+ if (nr_pages) {
+ struct mem_cgroup *memcg;
+
+ memcg = get_mem_cgroup_from_objcg(old);
+
+ if (!cgroup_subsys_on_dfl(memory_cgrp_subsys))
+ page_counter_uncharge(&memcg->kmem, nr_pages);
+
+ __refill_stock(memcg, nr_pages);
+
+ css_put(&memcg->css);
+ }
/*
* The leftover is flushed to the centralized per-memcg value.