Currently, ->pd_stat() is called only when moduleparam
blkcg_debug_stats is set which prevents it from printing non-debug
policy-specific statistics. Let's move debug testing down so that
->pd_stat() can print non-debug stat too. This patch doesn't cause
any visible behavior change.
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
---
block/blk-cgroup.c | 9 +++------
block/blk-iolatency.c | 3 +++
include/linux/blk-cgroup.h | 1 +
3 files changed, 7 insertions(+), 6 deletions(-)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -54,7 +54,7 @@ static struct blkcg_policy *blkcg_policy
static LIST_HEAD(all_blkcgs); /* protected by blkcg_pol_mutex */
-static bool blkcg_debug_stats = false;
+bool blkcg_debug_stats = false;
static struct workqueue_struct *blkcg_punt_bio_wq;
static bool blkcg_policy_enabled(struct request_queue *q,
@@ -968,10 +968,7 @@ static int blkcg_print_stat(struct seq_f
dbytes, dios);
}
- if (!blkcg_debug_stats)
- goto next;
-
- if (atomic_read(&blkg->use_delay)) {
+ if (blkcg_debug_stats && atomic_read(&blkg->use_delay)) {
has_stats = true;
off += scnprintf(buf+off, size-off,
" use_delay=%d delay_nsec=%llu",
@@ -991,7 +988,7 @@ static int blkcg_print_stat(struct seq_f
has_stats = true;
off += written;
}
-next:
+
if (has_stats) {
if (off < size - 1) {
off += scnprintf(buf+off, size-off, "\n");
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -917,6 +917,9 @@ static size_t iolatency_pd_stat(struct b
unsigned long long avg_lat;
unsigned long long cur_win;
+ if (!blkcg_debug_stats)
+ return 0;
+
if (iolat->ssd)
return iolatency_ssd_stat(iolat, buf, size);
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -182,6 +182,7 @@ struct blkcg_policy {
extern struct blkcg blkcg_root;
extern struct cgroup_subsys_state * const blkcg_root_css;
+extern bool blkcg_debug_stats;
struct blkcg_gq *blkg_lookup_slowpath(struct blkcg *blkcg,
struct request_queue *q, bool update_hint);
