blkcg: allow blkcg_policy->pd_stat() to print non-debug info too

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@kernel.org>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 24ed269..55a7dc2 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -54,7 +54,7 @@ static struct blkcg_policy *blkcg_policy[BLKCG_MAX_POLS];
 
 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,
@@ -944,10 +944,7 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
                                         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",
@@ -967,7 +964,7 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
                                has_stats = true;
                        off += written;
                }
-next:
+
                if (has_stats) {
                        if (off < size - 1) {
                                off += scnprintf(buf+off, size-off, "\n");

diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index d973c38..0fff7b5 100644 (file)
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -917,6 +917,9 @@ static size_t iolatency_pd_stat(struct blkg_policy_data *pd, char *buf,
        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);
 

diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index 689a582..1281109 100644 (file)
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -181,6 +181,7 @@ 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);