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 <[email protected]> Cc: Josef Bacik <[email protected]> --- 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);
