| Message ID | 20230824034304.37411-32-zhengqi.arch@bytedance.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | use refcount+RCU method to implement lockless slab shrink | expand |
On Thu 24-08-23 11:42:50, Qi Zheng wrote: > 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. > > Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> > Reviewed-by: Muchun Song <songmuchun@bytedance.com> > CC: "Theodore Ts'o" <tytso@mit.edu> > CC: Jan Kara <jack@suse.com> > CC: linux-ext4@vger.kernel.org Looks good to me. Feel free to add: Acked-by: Jan Kara <jack@suse.cz> Honza > --- > fs/jbd2/journal.c | 30 +++++++++++++++++++----------- > include/linux/jbd2.h | 2 +- > 2 files changed, 20 insertions(+), 12 deletions(-) > > diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c > index 768fa05bcbed..75692baa76e8 100644 > --- a/fs/jbd2/journal.c > +++ b/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_scan(struct shrinker *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 +1588,22 @@ static journal_t *journal_init_common(struct block_device *bdev, > 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->seeks = DEFAULT_SEEKS; > + journal->j_shrinker->batch = journal->j_max_transaction_buffers; > + journal->j_shrinker->private_data = journal; > + > + shrinker_register(journal->j_shrinker); > > return journal; > > @@ -2170,9 +2178,9 @@ int jbd2_journal_destroy(journal_t *journal) > 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); > diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h > index 52772c826c86..6dcbb4eb80fb 100644 > --- a/include/linux/jbd2.h > +++ b/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: > -- > 2.30.2 >
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 768fa05bcbed..75692baa76e8 100644 --- a/fs/jbd2/journal.c +++ b/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_scan(struct shrinker *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 +1588,22 @@ static journal_t *journal_init_common(struct block_device *bdev, 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->seeks = DEFAULT_SEEKS; + journal->j_shrinker->batch = journal->j_max_transaction_buffers; + journal->j_shrinker->private_data = journal; + + shrinker_register(journal->j_shrinker); return journal; @@ -2170,9 +2178,9 @@ int jbd2_journal_destroy(journal_t *journal) 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); diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 52772c826c86..6dcbb4eb80fb 100644 --- a/include/linux/jbd2.h +++ b/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: