The patch titled
Subject: mm: shrinker: convert shrinker_rwsem to mutex
has been added to the -mm mm-unstable branch. Its filename is
mm-shrinker-convert-shrinker_rwsem-to-mutex.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-shrinker-convert-shrinker_rwsem-to-mutex.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: mm: shrinker: convert shrinker_rwsem to mutex
Date: Mon, 11 Sep 2023 17:44:44 +0800
Now there are no readers of shrinker_rwsem, so we can simply replace it
with mutex lock.
Link: https://lkml.kernel.org/r/20230911094444.68966-46-zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Cc: Alasdair Kergon <agk@xxxxxxxxxx>
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@xxxxxxxxxxxxx>
Cc: Andreas Dilger <adilger.kernel@xxxxxxxxx>
Cc: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Cc: Anna Schumaker <anna@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Bob Peterson <rpeterso@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Carlos Llamas <cmllamas@xxxxxxxxxx>
Cc: Chandan Babu R <chandan.babu@xxxxxxxxxx>
Cc: Chao Yu <chao@xxxxxxxxxx>
Cc: Chris Mason <clm@xxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Christian Koenig <christian.koenig@xxxxxxx>
Cc: Chuck Lever <cel@xxxxxxxxxx>
Cc: Coly Li <colyli@xxxxxxx>
Cc: Dai Ngo <Dai.Ngo@xxxxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: "Darrick J. Wong" <djwong@xxxxxxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Sterba <dsterba@xxxxxxxx>
Cc: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Cc: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Huang Rui <ray.huang@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Jason Wang <jasowang@xxxxxxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: Jeffle Xu <jefflexu@xxxxxxxxxxxxxxxxx>
Cc: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Kirill Tkhai <tkhai@xxxxx>
Cc: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx>
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Neil Brown <neilb@xxxxxxx>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
Cc: Olga Kornievskaia <kolga@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Richard Weinberger <richard@xxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Sean Paul <sean@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Cc: Song Liu <song@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Steven Price <steven.price@xxxxxxx>
Cc: "Theodore Ts'o" <tytso@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
Cc: Tom Talpey <tom@xxxxxxxxxx>
Cc: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Cc: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
Cc: Yue Hu <huyue2@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/md/dm-cache-metadata.c | 2 +-
fs/super.c | 2 +-
mm/shrinker.c | 28 ++++++++++++++--------------
mm/shrinker_debug.c | 14 +++++++-------
4 files changed, 23 insertions(+), 23 deletions(-)
--- a/drivers/md/dm-cache-metadata.c~mm-shrinker-convert-shrinker_rwsem-to-mutex
+++ a/drivers/md/dm-cache-metadata.c
@@ -1828,7 +1828,7 @@ int dm_cache_metadata_abort(struct dm_ca
* Replacement block manager (new_bm) is created and old_bm destroyed outside of
* cmd root_lock to avoid ABBA deadlock that would result (due to life-cycle of
* shrinker associated with the block manager's bufio client vs cmd root_lock).
- * - must take shrinker_rwsem without holding cmd->root_lock
+ * - must take shrinker_mutex without holding cmd->root_lock
*/
new_bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT,
CACHE_MAX_CONCURRENT_LOCKS);
--- a/fs/super.c~mm-shrinker-convert-shrinker_rwsem-to-mutex
+++ a/fs/super.c
@@ -178,7 +178,7 @@ static void super_wake(struct super_bloc
* One thing we have to be careful of with a per-sb shrinker is that we don't
* drop the last active reference to the superblock from within the shrinker.
* If that happens we could trigger unregistering the shrinker from within the
- * shrinker path and that leads to deadlock on the shrinker_rwsem. Hence we
+ * shrinker path and that leads to deadlock on the shrinker_mutex. Hence we
* take a passive reference to the superblock to avoid this from occurring.
*/
static unsigned long super_cache_scan(struct shrinker *shrink,
--- a/mm/shrinker.c~mm-shrinker-convert-shrinker_rwsem-to-mutex
+++ a/mm/shrinker.c
@@ -8,7 +8,7 @@
#include "internal.h"
LIST_HEAD(shrinker_list);
-DECLARE_RWSEM(shrinker_rwsem);
+DEFINE_MUTEX(shrinker_mutex);
#ifdef CONFIG_MEMCG
static int shrinker_nr_max;
@@ -80,7 +80,7 @@ int alloc_shrinker_info(struct mem_cgrou
int nid, ret = 0;
int array_size = 0;
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
array_size = shrinker_unit_size(shrinker_nr_max);
for_each_node(nid) {
info = kvzalloc_node(sizeof(*info) + array_size, GFP_KERNEL, nid);
@@ -91,7 +91,7 @@ int alloc_shrinker_info(struct mem_cgrou
goto err;
rcu_assign_pointer(memcg->nodeinfo[nid]->shrinker_info, info);
}
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
return ret;
@@ -104,7 +104,7 @@ static struct shrinker_info *shrinker_in
int nid)
{
return rcu_dereference_protected(memcg->nodeinfo[nid]->shrinker_info,
- lockdep_is_held(&shrinker_rwsem));
+ lockdep_is_held(&shrinker_mutex));
}
static int expand_one_shrinker_info(struct mem_cgroup *memcg, int new_size,
@@ -154,7 +154,7 @@ static int expand_shrinker_info(int new_
if (!root_mem_cgroup)
goto out;
- lockdep_assert_held(&shrinker_rwsem);
+ lockdep_assert_held(&shrinker_mutex);
new_size = shrinker_unit_size(new_nr_max);
old_size = shrinker_unit_size(shrinker_nr_max);
@@ -217,7 +217,7 @@ static int shrinker_memcg_alloc(struct s
if (mem_cgroup_disabled())
return -ENOSYS;
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
id = idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL);
if (id < 0)
goto unlock;
@@ -231,7 +231,7 @@ static int shrinker_memcg_alloc(struct s
shrinker->id = id;
ret = 0;
unlock:
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
return ret;
}
@@ -241,7 +241,7 @@ static void shrinker_memcg_remove(struct
BUG_ON(id < 0);
- lockdep_assert_held(&shrinker_rwsem);
+ lockdep_assert_held(&shrinker_mutex);
idr_remove(&shrinker_idr, id);
}
@@ -292,7 +292,7 @@ void reparent_shrinker_deferred(struct m
parent = root_mem_cgroup;
/* Prevent from concurrent shrinker_info expand */
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
for_each_node(nid) {
child_info = shrinker_info_protected(memcg, nid);
parent_info = shrinker_info_protected(parent, nid);
@@ -305,7 +305,7 @@ void reparent_shrinker_deferred(struct m
}
}
}
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
}
#else
static int shrinker_memcg_alloc(struct shrinker *shrinker)
@@ -735,11 +735,11 @@ void shrinker_register(struct shrinker *
return;
}
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
list_add_tail_rcu(&shrinker->list, &shrinker_list);
shrinker->flags |= SHRINKER_REGISTERED;
shrinker_debugfs_add(shrinker);
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
init_completion(&shrinker->done);
/*
@@ -779,7 +779,7 @@ void shrinker_free(struct shrinker *shri
wait_for_completion(&shrinker->done);
}
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
if (shrinker->flags & SHRINKER_REGISTERED) {
/*
* Now we can safely remove it from the shrinker_list and then
@@ -794,7 +794,7 @@ void shrinker_free(struct shrinker *shri
if (shrinker->flags & SHRINKER_MEMCG_AWARE)
shrinker_memcg_remove(shrinker);
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
if (debugfs_entry)
shrinker_debugfs_remove(debugfs_entry, debugfs_id);
--- a/mm/shrinker_debug.c~mm-shrinker-convert-shrinker_rwsem-to-mutex
+++ a/mm/shrinker_debug.c
@@ -9,7 +9,7 @@
#include "internal.h"
/* defined in vmscan.c */
-extern struct rw_semaphore shrinker_rwsem;
+extern struct mutex shrinker_mutex;
extern struct list_head shrinker_list;
static DEFINE_IDA(shrinker_debugfs_ida);
@@ -165,7 +165,7 @@ int shrinker_debugfs_add(struct shrinker
char buf[128];
int id;
- lockdep_assert_held(&shrinker_rwsem);
+ lockdep_assert_held(&shrinker_mutex);
/* debugfs isn't initialized yet, add debugfs entries later. */
if (!shrinker_debugfs_root)
@@ -222,7 +222,7 @@ int shrinker_debugfs_rename(struct shrin
if (!new)
return -ENOMEM;
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
old = shrinker->name;
shrinker->name = new;
@@ -240,7 +240,7 @@ int shrinker_debugfs_rename(struct shrin
shrinker->debugfs_entry = entry;
}
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
kfree_const(old);
@@ -253,7 +253,7 @@ struct dentry *shrinker_debugfs_detach(s
{
struct dentry *entry = shrinker->debugfs_entry;
- lockdep_assert_held(&shrinker_rwsem);
+ lockdep_assert_held(&shrinker_mutex);
shrinker_debugfs_name_free(shrinker);
@@ -281,14 +281,14 @@ static int __init shrinker_debugfs_init(
shrinker_debugfs_root = dentry;
/* Create debugfs entries for shrinkers registered at boot */
- down_write(&shrinker_rwsem);
+ mutex_lock(&shrinker_mutex);
list_for_each_entry(shrinker, &shrinker_list, list)
if (!shrinker->debugfs_entry) {
ret = shrinker_debugfs_add(shrinker);
if (ret)
break;
}
- up_write(&shrinker_rwsem);
+ mutex_unlock(&shrinker_mutex);
return ret;
}
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
mm-move-some-shrinker-related-function-declarations-to-mm-internalh.patch
mm-vmscan-move-shrinker-related-code-into-a-separate-file.patch
mm-shrinker-remove-redundant-shrinker_rwsem-in-debugfs-operations.patch
drm-ttm-introduce-pool_shrink_rwsem.patch
mm-shrinker-add-infrastructure-for-dynamically-allocating-shrinker.patch
kvm-mmu-dynamically-allocate-the-x86-mmu-shrinker.patch
binder-dynamically-allocate-the-android-binder-shrinker.patch
drm-ttm-dynamically-allocate-the-drm-ttm_pool-shrinker.patch
xenbus-backend-dynamically-allocate-the-xen-backend-shrinker.patch
erofs-dynamically-allocate-the-erofs-shrinker.patch
f2fs-dynamically-allocate-the-f2fs-shrinker.patch
gfs2-dynamically-allocate-the-gfs2-glock-shrinker.patch
gfs2-dynamically-allocate-the-gfs2-qd-shrinker.patch
nfsv42-dynamically-allocate-the-nfs-xattr-shrinkers.patch
nfs-dynamically-allocate-the-nfs-acl-shrinker.patch
nfsd-dynamically-allocate-the-nfsd-filecache-shrinker.patch
quota-dynamically-allocate-the-dquota-cache-shrinker.patch
ubifs-dynamically-allocate-the-ubifs-slab-shrinker.patch
rcu-dynamically-allocate-the-rcu-lazy-shrinker.patch
rcu-dynamically-allocate-the-rcu-kfree-shrinker.patch
mm-thp-dynamically-allocate-the-thp-related-shrinkers.patch
sunrpc-dynamically-allocate-the-sunrpc_cred-shrinker.patch
mm-workingset-dynamically-allocate-the-mm-shadow-shrinker.patch
drm-i915-dynamically-allocate-the-i915_gem_mm-shrinker.patch
drm-msm-dynamically-allocate-the-drm-msm_gem-shrinker.patch
drm-panfrost-dynamically-allocate-the-drm-panfrost-shrinker.patch
dm-dynamically-allocate-the-dm-bufio-shrinker.patch
dm-zoned-dynamically-allocate-the-dm-zoned-meta-shrinker.patch
md-raid5-dynamically-allocate-the-md-raid5-shrinker.patch
bcache-dynamically-allocate-the-md-bcache-shrinker.patch
vmw_balloon-dynamically-allocate-the-vmw-balloon-shrinker.patch
virtio_balloon-dynamically-allocate-the-virtio-balloon-shrinker.patch
mbcache-dynamically-allocate-the-mbcache-shrinker.patch
ext4-dynamically-allocate-the-ext4-es-shrinker.patch
jbd2ext4-dynamically-allocate-the-jbd2-journal-shrinker.patch
nfsd-dynamically-allocate-the-nfsd-client-shrinker.patch
nfsd-dynamically-allocate-the-nfsd-reply-shrinker.patch
xfs-dynamically-allocate-the-xfs-buf-shrinker.patch
xfs-dynamically-allocate-the-xfs-inodegc-shrinker.patch
xfs-dynamically-allocate-the-xfs-qm-shrinker.patch
zsmalloc-dynamically-allocate-the-mm-zspool-shrinker.patch
fs-super-dynamically-allocate-the-s_shrink.patch
mm-shrinker-remove-old-apis.patch
mm-shrinker-add-a-secondary-array-for-shrinker_info-map-nr_deferred.patch
mm-shrinker-rename-preallocunregister_memcg_shrinker-to-shrinker_memcg_allocremove.patch
mm-shrinker-make-global-slab-shrink-lockless.patch
mm-shrinker-make-memcg-slab-shrink-lockless.patch
mm-shrinker-hold-write-lock-to-reparent-shrinker-nr_deferred.patch
mm-shrinker-convert-shrinker_rwsem-to-mutex.patch
