From: Qi Zheng <qi.zheng@linux.dev>
To: akpm@linux-foundation.org, tkhai@ya.ru, roman.gushchin@linux.dev,
vbabka@suse.cz, viro@zeniv.linux.org.uk, brauner@kernel.org,
djwong@kernel.org, hughd@google.com, paulmck@kernel.org,
muchun.song@linux.dev
Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
linux-xfs@vger.kernel.org, linux-kernel@vger.kernel.org,
Qi Zheng <zhengqi.arch@bytedance.com>
Subject: [PATCH 2/8] mm: vmscan: split unregister_shrinker()
Date: Wed, 31 May 2023 09:57:36 +0000 [thread overview]
Message-ID: <20230531095742.2480623-3-qi.zheng@linux.dev> (raw)
In-Reply-To: <20230531095742.2480623-1-qi.zheng@linux.dev>
From: Kirill Tkhai <tkhai@ya.ru>
This and the next patches in this series aim to make
time effect of synchronize_srcu() invisible for user.
The patch splits unregister_shrinker() in two functions:
unregister_shrinker_delayed_initiate()
unregister_shrinker_delayed_finalize()
and shrinker users may make the second of them to be called
asynchronous (e.g., from workqueue). Next patches make
superblock shrinker to follow this way, so user-visible
umount() time won't contain delays from synchronize_srcu().
Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
---
include/linux/shrinker.h | 2 ++
mm/vmscan.c | 22 ++++++++++++++++++----
2 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/include/linux/shrinker.h b/include/linux/shrinker.h
index 224293b2dd06..e9d5a19d83fe 100644
--- a/include/linux/shrinker.h
+++ b/include/linux/shrinker.h
@@ -102,6 +102,8 @@ extern void register_shrinker_prepared(struct shrinker *shrinker);
extern int __printf(2, 3) register_shrinker(struct shrinker *shrinker,
const char *fmt, ...);
extern void unregister_shrinker(struct shrinker *shrinker);
+extern void unregister_shrinker_delayed_initiate(struct shrinker *shrinker);
+extern void unregister_shrinker_delayed_finalize(struct shrinker *shrinker);
extern void free_prealloced_shrinker(struct shrinker *shrinker);
extern void synchronize_shrinkers(void);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index a773e97e152e..baf8d2327d70 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -799,10 +799,7 @@ int register_shrinker(struct shrinker *shrinker, const char *fmt, ...)
#endif
EXPORT_SYMBOL(register_shrinker);
-/*
- * Remove one
- */
-void unregister_shrinker(struct shrinker *shrinker)
+void unregister_shrinker_delayed_initiate(struct shrinker *shrinker)
{
struct dentry *debugfs_entry;
int debugfs_id;
@@ -819,6 +816,13 @@ void unregister_shrinker(struct shrinker *shrinker)
mutex_unlock(&shrinker_mutex);
shrinker_debugfs_remove(debugfs_entry, debugfs_id);
+}
+EXPORT_SYMBOL(unregister_shrinker_delayed_initiate);
+
+void unregister_shrinker_delayed_finalize(struct shrinker *shrinker)
+{
+ if (!shrinker->nr_deferred)
+ return;
atomic_inc(&shrinker_srcu_generation);
synchronize_srcu(&shrinker_srcu);
@@ -826,6 +830,16 @@ void unregister_shrinker(struct shrinker *shrinker)
kfree(shrinker->nr_deferred);
shrinker->nr_deferred = NULL;
}
+EXPORT_SYMBOL(unregister_shrinker_delayed_finalize);
+
+/*
+ * Remove one
+ */
+void unregister_shrinker(struct shrinker *shrinker)
+{
+ unregister_shrinker_delayed_initiate(shrinker);
+ unregister_shrinker_delayed_finalize(shrinker);
+}
EXPORT_SYMBOL(unregister_shrinker);
/**
--
2.30.2
next prev parent reply other threads:[~2023-05-31 9:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-31 9:57 [PATCH 0/8] make unregistration of super_block shrinker more faster Qi Zheng
2023-05-31 9:57 ` [PATCH 1/8] mm: vmscan: move shrinker_debugfs_remove() before synchronize_srcu() Qi Zheng
2023-05-31 10:49 ` Christian Brauner
2023-05-31 12:52 ` Qi Zheng
2023-05-31 9:57 ` Qi Zheng [this message]
2023-05-31 9:57 ` [PATCH 3/8] fs: move list_lru_destroy() to destroy_super_work() Qi Zheng
2023-05-31 9:57 ` [PATCH 4/8] fs: shrink only (SB_ACTIVE|SB_BORN) superblocks in super_cache_scan() Qi Zheng
2023-05-31 9:57 ` [PATCH 5/8] fs: introduce struct super_operations::destroy_super() callback Qi Zheng
2023-05-31 11:19 ` Christian Brauner
2023-05-31 12:54 ` Qi Zheng
2023-05-31 9:57 ` [PATCH 6/8] xfs: introduce xfs_fs_destroy_super() Qi Zheng
2023-05-31 9:57 ` [PATCH 7/8] shmem: implement shmem_destroy_super() Qi Zheng
2023-05-31 9:57 ` [PATCH 8/8] fs: use unregister_shrinker_delayed_{initiate, finalize} for super_block shrinker Qi Zheng
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