From: Yang Shi <shy828301@gmail.com>
To: guro@fb.com, ktkhai@virtuozzo.com, vbabka@suse.cz,
shakeelb@google.com, david@fromorbit.com, hannes@cmpxchg.org,
mhocko@suse.com, akpm@linux-foundation.org
Cc: shy828301@gmail.com, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [v7 PATCH 07/12] mm: vmscan: use a new flag to indicate shrinker is registered
Date: Tue, 9 Feb 2021 09:46:41 -0800 [thread overview]
Message-ID: <20210209174646.1310591-8-shy828301@gmail.com> (raw)
In-Reply-To: <20210209174646.1310591-1-shy828301@gmail.com>
Currently registered shrinker is indicated by non-NULL shrinker->nr_deferred.
This approach is fine with nr_deferred at the shrinker level, but the following
patches will move MEMCG_AWARE shrinkers' nr_deferred to memcg level, so their
shrinker->nr_deferred would always be NULL. This would prevent the shrinkers
from unregistering correctly.
Remove SHRINKER_REGISTERING since we could check if shrinker is registered
successfully by the new flag.
Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
---
include/linux/shrinker.h | 7 ++++---
mm/vmscan.c | 31 +++++++++----------------------
2 files changed, 13 insertions(+), 25 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 0f80123650e2..1eac79ce57d4 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -79,13 +79,14 @@ struct shrinker {
#define DEFAULT_SEEKS 2 /* A good number if you don't know better. */
/* Flags */
-#define SHRINKER_NUMA_AWARE (1 << 0)
-#define SHRINKER_MEMCG_AWARE (1 << 1)
+#define SHRINKER_REGISTERED (1 << 0)
+#define SHRINKER_NUMA_AWARE (1 << 1)
+#define SHRINKER_MEMCG_AWARE (1 << 2)
/*
* It just makes sense when the shrinker is also MEMCG_AWARE for now,
* non-MEMCG_AWARE shrinker should not have this flag set.
*/
-#define SHRINKER_NONSLAB (1 << 2)
+#define SHRINKER_NONSLAB (1 << 3)
extern int prealloc_shrinker(struct shrinker *shrinker);
extern void register_shrinker_prepared(struct shrinker *shrinker);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 273efbf4d53c..a047980536cf 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -315,19 +315,6 @@ void set_shrinker_bit(struct mem_cgroup *memcg, int nid, int shrinker_id)
}
}
-/*
- * We allow subsystems to populate their shrinker-related
- * LRU lists before register_shrinker_prepared() is called
- * for the shrinker, since we don't want to impose
- * restrictions on their internal registration order.
- * In this case shrink_slab_memcg() may find corresponding
- * bit is set in the shrinkers map.
- *
- * This value is used by the function to detect registering
- * shrinkers and to skip do_shrink_slab() calls for them.
- */
-#define SHRINKER_REGISTERING ((struct shrinker *)~0UL)
-
static DEFINE_IDR(shrinker_idr);
static int prealloc_memcg_shrinker(struct shrinker *shrinker)
@@ -336,7 +323,7 @@ static int prealloc_memcg_shrinker(struct shrinker *shrinker)
down_write(&shrinker_rwsem);
/* This may call shrinker, so it must use down_read_trylock() */
- id = idr_alloc(&shrinker_idr, SHRINKER_REGISTERING, 0, 0, GFP_KERNEL);
+ id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL);
if (id < 0)
goto unlock;
@@ -499,10 +486,7 @@ void register_shrinker_prepared(struct shrinker *shrinker)
{
down_write(&shrinker_rwsem);
list_add_tail(&shrinker->list, &shrinker_list);
-#ifdef CONFIG_MEMCG
- if (shrinker->flags & SHRINKER_MEMCG_AWARE)
- idr_replace(&shrinker_idr, shrinker, shrinker->id);
-#endif
+ shrinker->flags |= SHRINKER_REGISTERED;
up_write(&shrinker_rwsem);
}
@@ -522,13 +506,16 @@ EXPORT_SYMBOL(register_shrinker);
*/
void unregister_shrinker(struct shrinker *shrinker)
{
- if (!shrinker->nr_deferred)
+ if (!(shrinker->flags & SHRINKER_REGISTERED))
return;
- if (shrinker->flags & SHRINKER_MEMCG_AWARE)
- unregister_memcg_shrinker(shrinker);
+
down_write(&shrinker_rwsem);
list_del(&shrinker->list);
+ shrinker->flags &= ~SHRINKER_REGISTERED;
up_write(&shrinker_rwsem);
+
+ if (shrinker->flags & SHRINKER_MEMCG_AWARE)
+ unregister_memcg_shrinker(shrinker);
kfree(shrinker->nr_deferred);
shrinker->nr_deferred = NULL;
}
@@ -693,7 +680,7 @@ static unsigned long shrink_slab_memcg(gfp_t gfp_mask, int nid,
struct shrinker *shrinker;
shrinker = idr_find(&shrinker_idr, i);
- if (unlikely(!shrinker || shrinker == SHRINKER_REGISTERING)) {
+ if (unlikely(!shrinker || !(shrinker->flags & SHRINKER_REGISTERED))) {
if (!shrinker)
clear_bit(i, info->map);
continue;
--
2.26.2
next prev parent reply other threads:[~2021-02-09 18:41 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-09 17:46 [v7 PATCH 0/12] Make shrinker's nr_deferred memcg aware Yang Shi
2021-02-09 17:46 ` [v7 PATCH 01/12] mm: vmscan: use nid from shrink_control for tracepoint Yang Shi
2021-02-09 19:14 ` Shakeel Butt
2021-02-10 16:58 ` Yang Shi
2021-02-09 19:21 ` Roman Gushchin
2021-02-09 17:46 ` [v7 PATCH 02/12] mm: vmscan: consolidate shrinker_maps handling code Yang Shi
2021-02-09 20:27 ` Roman Gushchin
2021-02-10 14:19 ` Shakeel Butt
2021-02-09 17:46 ` [v7 PATCH 03/12] mm: vmscan: use shrinker_rwsem to protect shrinker_maps allocation Yang Shi
2021-02-09 20:33 ` Roman Gushchin
2021-02-09 23:28 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 04/12] mm: vmscan: remove memcg_shrinker_map_size Yang Shi
2021-02-09 20:43 ` Roman Gushchin
2021-02-09 23:31 ` Yang Shi
2021-02-10 18:14 ` Vlastimil Babka
2021-02-09 17:46 ` [v7 PATCH 05/12] mm: memcontrol: rename shrinker_map to shrinker_info Yang Shi
2021-02-09 20:50 ` Roman Gushchin
2021-02-09 23:33 ` Yang Shi
2021-02-10 0:16 ` Roman Gushchin
2021-02-11 16:47 ` Kirill Tkhai
2021-02-11 17:29 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 06/12] mm: vmscan: add shrinker_info_protected() helper Yang Shi
2021-02-10 0:22 ` Roman Gushchin
2021-02-10 1:07 ` Yang Shi
2021-02-10 1:29 ` Roman Gushchin
2021-02-10 12:12 ` Kirill Tkhai
2021-02-10 18:17 ` Vlastimil Babka
2021-02-12 6:54 ` [mm] bd741fb2ad: WARNING:suspicious_RCU_usage kernel test robot
2021-02-09 17:46 ` Yang Shi [this message]
2021-02-10 0:39 ` [v7 PATCH 07/12] mm: vmscan: use a new flag to indicate shrinker is registered Roman Gushchin
2021-02-10 1:12 ` Yang Shi
2021-02-10 1:34 ` Roman Gushchin
2021-02-10 1:55 ` Yang Shi
2021-02-10 18:45 ` Yang Shi
2021-02-10 18:23 ` Vlastimil Babka
2021-02-09 17:46 ` [v7 PATCH 08/12] mm: vmscan: add per memcg shrinker nr_deferred Yang Shi
2021-02-10 1:10 ` Roman Gushchin
2021-02-10 1:25 ` Yang Shi
2021-02-10 1:40 ` Roman Gushchin
2021-02-10 1:57 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 09/12] mm: vmscan: use per memcg nr_deferred of shrinker Yang Shi
2021-02-10 1:27 ` Roman Gushchin
2021-02-10 1:52 ` Yang Shi
2021-02-10 14:36 ` Kirill Tkhai
2021-02-10 16:41 ` Yang Shi
2021-02-09 17:46 ` [v7 PATCH 10/12] mm: vmscan: don't need allocate shrinker->nr_deferred for memcg aware shrinkers Yang Shi
2021-02-10 1:23 ` Roman Gushchin
2021-02-09 17:46 ` [v7 PATCH 11/12] mm: memcontrol: reparent nr_deferred when memcg offline Yang Shi
2021-02-10 1:18 ` Roman Gushchin
2021-02-09 17:46 ` [v7 PATCH 12/12] mm: vmscan: shrink deferred objects proportional to priority Yang Shi
2021-02-11 13:10 ` Vlastimil Babka
2021-02-11 17:29 ` Yang Shi
2021-02-11 18:52 ` Vlastimil Babka
2021-02-11 19:15 ` Yang Shi
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