bcache: add reclaimed_journal_buckets to struct cache_set

Now we have counters for how many times jouranl is reclaimed, how many
times cached dirty btree nodes are flushed, but we don't know how many
jouranl buckets are really reclaimed.

This patch adds reclaimed_journal_buckets into struct cache_set, this
is an increasing only counter, to tell how many journal buckets are
reclaimed since cache set runs. From all these three counters (reclaim,
reclaimed_journal_buckets, flush_write), we can have idea how well
current journal space reclaim code works.

Signed-off-by: Coly Li <colyli@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 3539624..013e35a 100644 (file)
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -705,6 +705,7 @@ struct cache_set {
        atomic_long_t           writeback_keys_failed;
 
        atomic_long_t           reclaim;
+       atomic_long_t           reclaimed_journal_buckets;
        atomic_long_t           flush_write;
 
        enum                    {

diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index 8bcd8f1..be2a2a2 100644 (file)
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -614,6 +614,7 @@ static void journal_reclaim(struct cache_set *c)
                k->ptr[n++] = MAKE_PTR(0,
                                  bucket_to_sector(c, ca->sb.d[ja->cur_idx]),
                                  ca->sb.nr_this_dev);
+               atomic_long_inc(&c->reclaimed_journal_buckets);
        }
 
        if (n) {

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 701a386..9f08267 100644 (file)
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -82,6 +82,7 @@ read_attribute(bset_tree_stats);
 read_attribute(state);
 read_attribute(cache_read_races);
 read_attribute(reclaim);
+read_attribute(reclaimed_journal_buckets);
 read_attribute(flush_write);
 read_attribute(writeback_keys_done);
 read_attribute(writeback_keys_failed);
@@ -705,6 +706,9 @@ SHOW(__bch_cache_set)
        sysfs_print(reclaim,
                    atomic_long_read(&c->reclaim));
 
+       sysfs_print(reclaimed_journal_buckets,
+                   atomic_long_read(&c->reclaimed_journal_buckets));
+
        sysfs_print(flush_write,
                    atomic_long_read(&c->flush_write));
 
@@ -931,6 +935,7 @@ static struct attribute *bch_cache_set_internal_files[] = {
        &sysfs_bset_tree_stats,
        &sysfs_cache_read_races,
        &sysfs_reclaim,
+       &sysfs_reclaimed_journal_buckets,
        &sysfs_flush_write,
        &sysfs_writeback_keys_done,
        &sysfs_writeback_keys_failed,