Re: [PATCH v3 34/49] ext4: dynamically allocate the ext4-es shrinker
From: Qi Zheng <hidden>
Date: 2023-07-27 09:28:25
Also in:
dm-devel, dri-devel, kvm, linux-arm-msm, linux-bcache, linux-btrfs, linux-ext4, linux-f2fs-devel, linux-fsdevel, linux-mm, linux-nfs, linux-raid, linux-xfs, lkml, rcu, xen-devel
On 2023/7/27 16:04, Qi Zheng wrote:
quoted hunk ↗ jump to hunk
In preparation for implementing lockless slab shrink, use new APIs to dynamically allocate the ext4-es shrinker, so that it can be freed asynchronously using kfree_rcu(). Then it doesn't need to wait for RCU read-side critical section when releasing the struct ext4_sb_info. Signed-off-by: Qi Zheng <redacted> Reviewed-by: Muchun Song <redacted> --- fs/ext4/ext4.h | 2 +- fs/ext4/extents_status.c | 22 ++++++++++++---------- 2 files changed, 13 insertions(+), 11 deletions(-)diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 1e2259d9967d..82397bf0b33e 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h@@ -1657,7 +1657,7 @@ struct ext4_sb_info { __u32 s_csum_seed; /* Reclaim extents from extent status tree */ - struct shrinker s_es_shrinker; + struct shrinker *s_es_shrinker; struct list_head s_es_list; /* List of inodes with reclaimable extents */ long s_es_nr_inode; struct ext4_es_stats s_es_stats;diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 9b5b8951afb4..74bb64fadbc4 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c@@ -1596,7 +1596,7 @@ static unsigned long ext4_es_count(struct shrinker *shrink, unsigned long nr; struct ext4_sb_info *sbi; - sbi = container_of(shrink, struct ext4_sb_info, s_es_shrinker); + sbi = shrink->private_data; nr = percpu_counter_read_positive(&sbi->s_es_stats.es_stats_shk_cnt); trace_ext4_es_shrink_count(sbi->s_sb, sc->nr_to_scan, nr); return nr;@@ -1605,8 +1605,7 @@ static unsigned long ext4_es_count(struct shrinker *shrink, static unsigned long ext4_es_scan(struct shrinker *shrink, struct shrink_control *sc) { - struct ext4_sb_info *sbi = container_of(shrink, - struct ext4_sb_info, s_es_shrinker); + struct ext4_sb_info *sbi = shrink->private_data; int nr_to_scan = sc->nr_to_scan; int ret, nr_shrunk;@@ -1690,14 +1689,17 @@ int ext4_es_register_shrinker(struct ext4_sb_info *sbi) if (err) goto err3; - sbi->s_es_shrinker.scan_objects = ext4_es_scan; - sbi->s_es_shrinker.count_objects = ext4_es_count; - sbi->s_es_shrinker.seeks = DEFAULT_SEEKS; - err = register_shrinker(&sbi->s_es_shrinker, "ext4-es:%s", - sbi->s_sb->s_id); - if (err) + sbi->s_es_shrinker = shrinker_alloc(0, "ext4-es:%s", sbi->s_sb->s_id); + if (!sbi->s_es_shrinker)
Here should set err to -ENOMEM, will fix.
quoted hunk ↗ jump to hunk
goto err4; + sbi->s_es_shrinker->scan_objects = ext4_es_scan; + sbi->s_es_shrinker->count_objects = ext4_es_count; + sbi->s_es_shrinker->seeks = DEFAULT_SEEKS; + sbi->s_es_shrinker->private_data = sbi; + + shrinker_register(sbi->s_es_shrinker); + return 0; err4: percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);@@ -1716,7 +1718,7 @@ void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi) percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses); percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt); percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt); - unregister_shrinker(&sbi->s_es_shrinker); + shrinker_free(sbi->s_es_shrinker); } /*