The patch titled Subject: jbd2,ext4: dynamically allocate the jbd2-journal shrinker has been added to the -mm mm-unstable branch. Its filename is jbd2ext4-dynamically-allocate-the-jbd2-journal-shrinker.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/jbd2ext4-dynamically-allocate-the-jbd2-journal-shrinker.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> Subject: jbd2,ext4: dynamically allocate the jbd2-journal shrinker Date: Mon, 11 Sep 2023 17:44:30 +0800 In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the jbd2-journal shrinker, so that it can be freed asynchronously via RCU. Then it doesn't need to wait for RCU read-side critical section when releasing the struct journal_s. Link: https://lkml.kernel.org/r/20230911094444.68966-32-zhengqi.arch@xxxxxxxxxxxxx Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> Reviewed-by: Muchun Song <songmuchun@xxxxxxxxxxxxx> Acked-by: Jan Kara <jack@xxxxxxx> Cc: "Theodore Ts'o" <tytso@xxxxxxx> 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: 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: 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: 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> --- fs/jbd2/journal.c | 29 ++++++++++++++++++----------- include/linux/jbd2.h | 2 +- 2 files changed, 19 insertions(+), 12 deletions(-) --- a/fs/jbd2/journal.c~jbd2ext4-dynamically-allocate-the-jbd2-journal-shrinker +++ a/fs/jbd2/journal.c @@ -1290,7 +1290,7 @@ static int jbd2_min_tag_size(void) static unsigned long jbd2_journal_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { - journal_t *journal = container_of(shrink, journal_t, j_shrinker); + journal_t *journal = shrink->private_data; unsigned long nr_to_scan = sc->nr_to_scan; unsigned long nr_shrunk; unsigned long count; @@ -1316,7 +1316,7 @@ static unsigned long jbd2_journal_shrink static unsigned long jbd2_journal_shrink_count(struct shrinker *shrink, struct shrink_control *sc) { - journal_t *journal = container_of(shrink, journal_t, j_shrinker); + journal_t *journal = shrink->private_data; unsigned long count; count = percpu_counter_read_positive(&journal->j_checkpoint_jh_count); @@ -1588,14 +1588,21 @@ static journal_t *journal_init_common(st goto err_cleanup; journal->j_shrink_transaction = NULL; - journal->j_shrinker.scan_objects = jbd2_journal_shrink_scan; - journal->j_shrinker.count_objects = jbd2_journal_shrink_count; - journal->j_shrinker.seeks = DEFAULT_SEEKS; - journal->j_shrinker.batch = journal->j_max_transaction_buffers; - err = register_shrinker(&journal->j_shrinker, "jbd2-journal:(%u:%u)", - MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev)); - if (err) + + journal->j_shrinker = shrinker_alloc(0, "jbd2-journal:(%u:%u)", + MAJOR(bdev->bd_dev), + MINOR(bdev->bd_dev)); + if (!journal->j_shrinker) { + err = -ENOMEM; goto err_cleanup; + } + + journal->j_shrinker->scan_objects = jbd2_journal_shrink_scan; + journal->j_shrinker->count_objects = jbd2_journal_shrink_count; + journal->j_shrinker->batch = journal->j_max_transaction_buffers; + journal->j_shrinker->private_data = journal; + + shrinker_register(journal->j_shrinker); return journal; @@ -2170,9 +2177,9 @@ int jbd2_journal_destroy(journal_t *jour brelse(journal->j_sb_buffer); } - if (journal->j_shrinker.flags & SHRINKER_REGISTERED) { + if (journal->j_shrinker) { percpu_counter_destroy(&journal->j_checkpoint_jh_count); - unregister_shrinker(&journal->j_shrinker); + shrinker_free(journal->j_shrinker); } if (journal->j_proc_entry) jbd2_stats_proc_exit(journal); --- a/include/linux/jbd2.h~jbd2ext4-dynamically-allocate-the-jbd2-journal-shrinker +++ a/include/linux/jbd2.h @@ -886,7 +886,7 @@ struct journal_s * Journal head shrinker, reclaim buffer's journal head which * has been written back. */ - struct shrinker j_shrinker; + struct shrinker *j_shrinker; /** * @j_checkpoint_jh_count: _ 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