blkcg: move io_service_bytes and io_serviced stats into blkcg_gq
Currently, both cfq-iosched and blk-throttle keep track of
io_service_bytes and io_serviced stats. While keeping track of them
separately may be useful during development, it doesn't make much
sense otherwise. Also, blk-throttle was counting bio's as IOs while
cfq-iosched request's, which is more confusing than informative.
This patch adds ->stat_bytes and ->stat_ios to blkg (blkcg_gq),
removes the counterparts from cfq-iosched and blk-throttle and let
them print from the common blkg counters. The common counters are
incremented during bio issue in blkcg_bio_issue_check().
The outputs are still filtered by whether the policy has
blkg_policy_data on a given blkg, so cfq's output won't show up if it
has never been used for a given blkg. The only times when the outputs
would differ significantly are when policies are attached on the fly
or elevators are switched back and forth. Those are quite exceptional
operations and I don't think they warrant keeping separate counters.
v3: Update blkio-controller.txt accordingly.
v2: Account IOs during bio issues instead of request completions so
that bio-based drivers can be handled the same way.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index e861cc1..a948d4d 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -177,10 +177,6 @@
struct cfqg_stats {
#ifdef CONFIG_CFQ_GROUP_IOSCHED
- /* total bytes transferred */
- struct blkg_rwstat service_bytes;
- /* total IOs serviced, post merge */
- struct blkg_rwstat serviced;
/* number of ios merged */
struct blkg_rwstat merged;
/* total time spent on device in ns, may not be accurate w/ queueing */
@@ -696,8 +692,6 @@
uint64_t bytes, int rw)
{
blkg_stat_add(&cfqg->stats.sectors, bytes >> 9);
- blkg_rwstat_add(&cfqg->stats.serviced, rw, 1);
- blkg_rwstat_add(&cfqg->stats.service_bytes, rw, bytes);
}
static inline void cfqg_stats_update_completion(struct cfq_group *cfqg,
@@ -717,8 +711,6 @@
static void cfqg_stats_reset(struct cfqg_stats *stats)
{
/* queued stats shouldn't be cleared */
- blkg_rwstat_reset(&stats->service_bytes);
- blkg_rwstat_reset(&stats->serviced);
blkg_rwstat_reset(&stats->merged);
blkg_rwstat_reset(&stats->service_time);
blkg_rwstat_reset(&stats->wait_time);
@@ -738,8 +730,6 @@
static void cfqg_stats_add_aux(struct cfqg_stats *to, struct cfqg_stats *from)
{
/* queued stats shouldn't be cleared */
- blkg_rwstat_add_aux(&to->service_bytes, &from->service_bytes);
- blkg_rwstat_add_aux(&to->serviced, &from->serviced);
blkg_rwstat_add_aux(&to->merged, &from->merged);
blkg_rwstat_add_aux(&to->service_time, &from->service_time);
blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
@@ -1544,8 +1534,6 @@
#ifdef CONFIG_CFQ_GROUP_IOSCHED
static void cfqg_stats_exit(struct cfqg_stats *stats)
{
- blkg_rwstat_exit(&stats->service_bytes);
- blkg_rwstat_exit(&stats->serviced);
blkg_rwstat_exit(&stats->merged);
blkg_rwstat_exit(&stats->service_time);
blkg_rwstat_exit(&stats->wait_time);
@@ -1566,9 +1554,7 @@
static int cfqg_stats_init(struct cfqg_stats *stats, gfp_t gfp)
{
- if (blkg_rwstat_init(&stats->service_bytes, gfp) ||
- blkg_rwstat_init(&stats->serviced, gfp) ||
- blkg_rwstat_init(&stats->merged, gfp) ||
+ if (blkg_rwstat_init(&stats->merged, gfp) ||
blkg_rwstat_init(&stats->service_time, gfp) ||
blkg_rwstat_init(&stats->wait_time, gfp) ||
blkg_rwstat_init(&stats->queued, gfp) ||
@@ -1994,13 +1980,13 @@
},
{
.name = "io_service_bytes",
- .private = offsetof(struct cfq_group, stats.service_bytes),
- .seq_show = cfqg_print_rwstat,
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_bytes,
},
{
.name = "io_serviced",
- .private = offsetof(struct cfq_group, stats.serviced),
- .seq_show = cfqg_print_rwstat,
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_ios,
},
{
.name = "io_service_time",
@@ -2036,13 +2022,13 @@
},
{
.name = "io_service_bytes_recursive",
- .private = offsetof(struct cfq_group, stats.service_bytes),
- .seq_show = cfqg_print_rwstat_recursive,
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_bytes_recursive,
},
{
.name = "io_serviced_recursive",
- .private = offsetof(struct cfq_group, stats.serviced),
- .seq_show = cfqg_print_rwstat_recursive,
+ .private = (unsigned long)&blkcg_policy_cfq,
+ .seq_show = blkg_print_stat_ios_recursive,
},
{
.name = "io_service_time_recursive",