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blkcg: introduce blkg_stat and blkg_rwstat
blkcg uses u64_stats_sync to avoid reading wrong u64 statistic values
on 32bit archs and some stat counters have subtypes to distinguish
read/writes and sync/async IOs. The stat code paths are confusing and
involve a lot of going back and forth between blkcg core and specific
policy implementations, and synchronization and subtype handling are
open coded in blkcg core.
This patch introduces struct blkg_stat and blkg_rwstat which, with
accompanying operations, encapsulate stat updating and accessing with
proper synchronization.
blkg_stat is simple u64 counter with 64bit read-access protection.
blkg_rwstat is the one with rw and [a]sync subcounters and takes @rw
flags to distinguish IO subtypes (%REQ_WRITE and %REQ_SYNC) and
replaces stat_sub_type indexed arrays.
All counters in blkio_group_stats and blkio_group_stats_cpu are
replaced with either blkg_stat or blkg_rwstat along with all users.
This does add one u64_stats_sync per counter and increase stats_sync
operations but they're empty/noops on 64bit archs and blkcg doesn't
have too many counters, especially with DEBUG_BLK_CGROUP off.
While the currently resulting code isn't necessarily simpler at the
moment, this will enable further clean up of blkcg stats code.
- BLKIO_STAT_{READ|WRITE|SYNC|ASYNC|TOTAL} renamed to
BLKG_RWSTAT_{READ|WRITE|SYNC|ASYNC|TOTAL}.
- blkg_stat_add() replaces blkio_add_stat() and
blkio_check_and_dec_stat(). Note that BUG_ON() on underflow in the
latter function no longer exists. It's *way* better to have
underflowed stat counters than oopsing.
- blkio_group_stats->dequeue is now a proper u64 stat counter instead
of ulong.
- reset_stats() updated to clear each stat counters individually and
BLKG_STATS_DEBUG_CLEAR_{START|SIZE} are removed.
- Some functions reconstruct rw flags from direction and sync
booleans. This will be removed by future patches.
Signed-off-by: Tejun Heo <tj@kernel.org>
This commit is contained in:
Tejun Heo
parent
2aa4a1523b
commit
edcb0722c6
@ -132,46 +132,6 @@ static inline void blkio_update_group_iops(struct blkio_group *blkg,
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}
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}
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/*
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* Add to the appropriate stat variable depending on the request type.
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* This should be called with queue_lock held.
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*/
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static void blkio_add_stat(uint64_t *stat, uint64_t add, bool direction,
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bool sync)
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{
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if (direction)
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stat[BLKIO_STAT_WRITE] += add;
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else
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stat[BLKIO_STAT_READ] += add;
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if (sync)
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stat[BLKIO_STAT_SYNC] += add;
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else
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stat[BLKIO_STAT_ASYNC] += add;
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}
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/*
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* Decrements the appropriate stat variable if non-zero depending on the
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* request type. Panics on value being zero.
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* This should be called with the queue_lock held.
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*/
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static void blkio_check_and_dec_stat(uint64_t *stat, bool direction, bool sync)
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{
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if (direction) {
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BUG_ON(stat[BLKIO_STAT_WRITE] == 0);
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stat[BLKIO_STAT_WRITE]--;
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} else {
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BUG_ON(stat[BLKIO_STAT_READ] == 0);
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stat[BLKIO_STAT_READ]--;
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}
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if (sync) {
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BUG_ON(stat[BLKIO_STAT_SYNC] == 0);
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stat[BLKIO_STAT_SYNC]--;
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} else {
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BUG_ON(stat[BLKIO_STAT_ASYNC] == 0);
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stat[BLKIO_STAT_ASYNC]--;
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}
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}
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#ifdef CONFIG_DEBUG_BLK_CGROUP
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/* This should be called with the queue_lock held. */
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static void blkio_set_start_group_wait_time(struct blkio_group *blkg,
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@ -198,7 +158,8 @@ static void blkio_update_group_wait_time(struct blkio_group_stats *stats)
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now = sched_clock();
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if (time_after64(now, stats->start_group_wait_time))
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stats->group_wait_time += now - stats->start_group_wait_time;
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blkg_stat_add(&stats->group_wait_time,
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now - stats->start_group_wait_time);
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blkio_clear_blkg_waiting(stats);
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}
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@ -212,7 +173,8 @@ static void blkio_end_empty_time(struct blkio_group_stats *stats)
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now = sched_clock();
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if (time_after64(now, stats->start_empty_time))
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stats->empty_time += now - stats->start_empty_time;
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blkg_stat_add(&stats->empty_time,
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now - stats->start_empty_time);
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blkio_clear_blkg_empty(stats);
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}
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@ -239,11 +201,9 @@ void blkiocg_update_idle_time_stats(struct blkio_group *blkg,
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if (blkio_blkg_idling(stats)) {
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unsigned long long now = sched_clock();
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if (time_after64(now, stats->start_idle_time)) {
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u64_stats_update_begin(&stats->syncp);
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stats->idle_time += now - stats->start_idle_time;
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u64_stats_update_end(&stats->syncp);
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}
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if (time_after64(now, stats->start_idle_time))
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blkg_stat_add(&stats->idle_time,
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now - stats->start_idle_time);
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blkio_clear_blkg_idling(stats);
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}
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}
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@ -256,13 +216,10 @@ void blkiocg_update_avg_queue_size_stats(struct blkio_group *blkg,
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lockdep_assert_held(blkg->q->queue_lock);
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u64_stats_update_begin(&stats->syncp);
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stats->avg_queue_size_sum +=
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stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] +
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stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE];
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stats->avg_queue_size_samples++;
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blkg_stat_add(&stats->avg_queue_size_sum,
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blkg_rwstat_sum(&stats->queued));
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blkg_stat_add(&stats->avg_queue_size_samples, 1);
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blkio_update_group_wait_time(stats);
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u64_stats_update_end(&stats->syncp);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_avg_queue_size_stats);
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@ -273,8 +230,7 @@ void blkiocg_set_start_empty_time(struct blkio_group *blkg,
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lockdep_assert_held(blkg->q->queue_lock);
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if (stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_READ] ||
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stats->stat_arr[BLKIO_STAT_QUEUED][BLKIO_STAT_WRITE])
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if (blkg_rwstat_sum(&stats->queued))
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return;
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/*
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@ -298,7 +254,7 @@ void blkiocg_update_dequeue_stats(struct blkio_group *blkg,
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lockdep_assert_held(blkg->q->queue_lock);
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pd->stats.dequeue += dequeue;
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blkg_stat_add(&pd->stats.dequeue, dequeue);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_dequeue_stats);
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#else
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@ -314,14 +270,12 @@ void blkiocg_update_io_add_stats(struct blkio_group *blkg,
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bool sync)
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{
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struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
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int rw = (direction ? REQ_WRITE : 0) | (sync ? REQ_SYNC : 0);
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lockdep_assert_held(blkg->q->queue_lock);
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u64_stats_update_begin(&stats->syncp);
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_QUEUED], 1, direction, sync);
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blkg_rwstat_add(&stats->queued, rw, 1);
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blkio_end_empty_time(stats);
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u64_stats_update_end(&stats->syncp);
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blkio_set_start_group_wait_time(blkg, pol, curr_blkg);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_io_add_stats);
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@ -331,13 +285,11 @@ void blkiocg_update_io_remove_stats(struct blkio_group *blkg,
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bool direction, bool sync)
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{
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struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
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int rw = (direction ? REQ_WRITE : 0) | (sync ? REQ_SYNC : 0);
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lockdep_assert_held(blkg->q->queue_lock);
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u64_stats_update_begin(&stats->syncp);
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blkio_check_and_dec_stat(stats->stat_arr[BLKIO_STAT_QUEUED], direction,
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sync);
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u64_stats_update_end(&stats->syncp);
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blkg_rwstat_add(&stats->queued, rw, -1);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_io_remove_stats);
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@ -350,12 +302,10 @@ void blkiocg_update_timeslice_used(struct blkio_group *blkg,
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lockdep_assert_held(blkg->q->queue_lock);
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u64_stats_update_begin(&stats->syncp);
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stats->time += time;
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blkg_stat_add(&stats->time, time);
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#ifdef CONFIG_DEBUG_BLK_CGROUP
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stats->unaccounted_time += unaccounted_time;
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blkg_stat_add(&stats->unaccounted_time, unaccounted_time);
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#endif
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u64_stats_update_end(&stats->syncp);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_timeslice_used);
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@ -367,6 +317,7 @@ void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
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struct blkio_policy_type *pol,
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uint64_t bytes, bool direction, bool sync)
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{
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int rw = (direction ? REQ_WRITE : 0) | (sync ? REQ_SYNC : 0);
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struct blkg_policy_data *pd = blkg->pd[pol->plid];
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struct blkio_group_stats_cpu *stats_cpu;
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unsigned long flags;
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@ -384,13 +335,10 @@ void blkiocg_update_dispatch_stats(struct blkio_group *blkg,
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stats_cpu = this_cpu_ptr(pd->stats_cpu);
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u64_stats_update_begin(&stats_cpu->syncp);
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stats_cpu->sectors += bytes >> 9;
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blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICED],
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1, direction, sync);
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blkio_add_stat(stats_cpu->stat_arr_cpu[BLKIO_STAT_CPU_SERVICE_BYTES],
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bytes, direction, sync);
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u64_stats_update_end(&stats_cpu->syncp);
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blkg_stat_add(&stats_cpu->sectors, bytes >> 9);
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blkg_rwstat_add(&stats_cpu->serviced, rw, 1);
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blkg_rwstat_add(&stats_cpu->service_bytes, rw, bytes);
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local_irq_restore(flags);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_dispatch_stats);
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@ -403,17 +351,15 @@ void blkiocg_update_completion_stats(struct blkio_group *blkg,
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{
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struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
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unsigned long long now = sched_clock();
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int rw = (direction ? REQ_WRITE : 0) | (sync ? REQ_SYNC : 0);
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lockdep_assert_held(blkg->q->queue_lock);
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u64_stats_update_begin(&stats->syncp);
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if (time_after64(now, io_start_time))
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_SERVICE_TIME],
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now - io_start_time, direction, sync);
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blkg_rwstat_add(&stats->service_time, rw, now - io_start_time);
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if (time_after64(io_start_time, start_time))
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_WAIT_TIME],
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io_start_time - start_time, direction, sync);
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u64_stats_update_end(&stats->syncp);
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blkg_rwstat_add(&stats->wait_time, rw,
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io_start_time - start_time);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_completion_stats);
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@ -423,12 +369,11 @@ void blkiocg_update_io_merged_stats(struct blkio_group *blkg,
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bool direction, bool sync)
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{
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struct blkio_group_stats *stats = &blkg->pd[pol->plid]->stats;
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int rw = (direction ? REQ_WRITE : 0) | (sync ? REQ_SYNC : 0);
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lockdep_assert_held(blkg->q->queue_lock);
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u64_stats_update_begin(&stats->syncp);
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blkio_add_stat(stats->stat_arr[BLKIO_STAT_MERGED], 1, direction, sync);
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u64_stats_update_end(&stats->syncp);
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blkg_rwstat_add(&stats->merged, rw, 1);
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}
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EXPORT_SYMBOL_GPL(blkiocg_update_io_merged_stats);
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@ -757,8 +702,9 @@ static void blkio_reset_stats_cpu(struct blkio_group *blkg, int plid)
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struct blkio_group_stats_cpu *sc =
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per_cpu_ptr(pd->stats_cpu, cpu);
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sc->sectors = 0;
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memset(sc->stat_arr_cpu, 0, sizeof(sc->stat_arr_cpu));
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blkg_rwstat_reset(&sc->service_bytes);
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blkg_rwstat_reset(&sc->serviced);
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blkg_stat_reset(&sc->sectors);
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}
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}
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@ -768,7 +714,6 @@ blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
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struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgroup);
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struct blkio_group *blkg;
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struct hlist_node *n;
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int i;
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spin_lock(&blkio_list_lock);
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spin_lock_irq(&blkcg->lock);
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@ -786,14 +731,18 @@ blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
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struct blkio_group_stats *stats = &pd->stats;
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/* queued stats shouldn't be cleared */
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for (i = 0; i < ARRAY_SIZE(stats->stat_arr); i++)
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if (i != BLKIO_STAT_QUEUED)
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memset(stats->stat_arr[i], 0,
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sizeof(stats->stat_arr[i]));
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stats->time = 0;
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blkg_rwstat_reset(&stats->merged);
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blkg_rwstat_reset(&stats->service_time);
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blkg_rwstat_reset(&stats->wait_time);
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blkg_stat_reset(&stats->time);
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#ifdef CONFIG_DEBUG_BLK_CGROUP
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memset((void *)stats + BLKG_STATS_DEBUG_CLEAR_START, 0,
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BLKG_STATS_DEBUG_CLEAR_SIZE);
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blkg_stat_reset(&stats->unaccounted_time);
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blkg_stat_reset(&stats->avg_queue_size_sum);
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blkg_stat_reset(&stats->avg_queue_size_samples);
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blkg_stat_reset(&stats->dequeue);
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blkg_stat_reset(&stats->group_wait_time);
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blkg_stat_reset(&stats->idle_time);
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blkg_stat_reset(&stats->empty_time);
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#endif
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blkio_reset_stats_cpu(blkg, pol->plid);
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}
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@ -804,7 +753,7 @@ blkiocg_reset_stats(struct cgroup *cgroup, struct cftype *cftype, u64 val)
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return 0;
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}
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static void blkio_get_key_name(enum stat_sub_type type, const char *dname,
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static void blkio_get_key_name(enum blkg_rwstat_type type, const char *dname,
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char *str, int chars_left, bool diskname_only)
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{
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snprintf(str, chars_left, "%s", dname);
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@ -817,19 +766,19 @@ static void blkio_get_key_name(enum stat_sub_type type, const char *dname,
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if (diskname_only)
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return;
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switch (type) {
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case BLKIO_STAT_READ:
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case BLKG_RWSTAT_READ:
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strlcat(str, " Read", chars_left);
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break;
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case BLKIO_STAT_WRITE:
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case BLKG_RWSTAT_WRITE:
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strlcat(str, " Write", chars_left);
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break;
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case BLKIO_STAT_SYNC:
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case BLKG_RWSTAT_SYNC:
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strlcat(str, " Sync", chars_left);
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break;
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case BLKIO_STAT_ASYNC:
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case BLKG_RWSTAT_ASYNC:
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strlcat(str, " Async", chars_left);
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break;
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case BLKIO_STAT_TOTAL:
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case BLKG_RWSTAT_TOTAL:
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strlcat(str, " Total", chars_left);
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break;
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default:
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@ -838,29 +787,34 @@ static void blkio_get_key_name(enum stat_sub_type type, const char *dname,
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}
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static uint64_t blkio_read_stat_cpu(struct blkio_group *blkg, int plid,
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enum stat_type_cpu type, enum stat_sub_type sub_type)
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enum stat_type_cpu type,
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enum blkg_rwstat_type sub_type)
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{
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struct blkg_policy_data *pd = blkg->pd[plid];
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u64 val = 0;
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int cpu;
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struct blkio_group_stats_cpu *stats_cpu;
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u64 val = 0, tval;
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if (pd->stats_cpu == NULL)
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return val;
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for_each_possible_cpu(cpu) {
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unsigned int start;
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stats_cpu = per_cpu_ptr(pd->stats_cpu, cpu);
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struct blkio_group_stats_cpu *stats_cpu =
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per_cpu_ptr(pd->stats_cpu, cpu);
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struct blkg_rwstat rws;
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do {
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start = u64_stats_fetch_begin(&stats_cpu->syncp);
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if (type == BLKIO_STAT_CPU_SECTORS)
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tval = stats_cpu->sectors;
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else
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tval = stats_cpu->stat_arr_cpu[type][sub_type];
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} while(u64_stats_fetch_retry(&stats_cpu->syncp, start));
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val += tval;
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switch (type) {
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case BLKIO_STAT_CPU_SECTORS:
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val += blkg_stat_read(&stats_cpu->sectors);
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break;
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case BLKIO_STAT_CPU_SERVICE_BYTES:
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rws = blkg_rwstat_read(&stats_cpu->service_bytes);
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val += rws.cnt[sub_type];
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break;
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case BLKIO_STAT_CPU_SERVICED:
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rws = blkg_rwstat_read(&stats_cpu->serviced);
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val += rws.cnt[sub_type];
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break;
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}
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}
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return val;
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@ -872,7 +826,7 @@ static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg, int plid,
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{
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uint64_t disk_total, val;
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char key_str[MAX_KEY_LEN];
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enum stat_sub_type sub_type;
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enum blkg_rwstat_type sub_type;
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if (type == BLKIO_STAT_CPU_SECTORS) {
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val = blkio_read_stat_cpu(blkg, plid, type, 0);
|
||||
@ -881,7 +835,7 @@ static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg, int plid,
|
||||
return val;
|
||||
}
|
||||
|
||||
for (sub_type = BLKIO_STAT_READ; sub_type < BLKIO_STAT_TOTAL;
|
||||
for (sub_type = BLKG_RWSTAT_READ; sub_type < BLKG_RWSTAT_NR;
|
||||
sub_type++) {
|
||||
blkio_get_key_name(sub_type, dname, key_str, MAX_KEY_LEN,
|
||||
false);
|
||||
@ -889,10 +843,10 @@ static uint64_t blkio_get_stat_cpu(struct blkio_group *blkg, int plid,
|
||||
cb->fill(cb, key_str, val);
|
||||
}
|
||||
|
||||
disk_total = blkio_read_stat_cpu(blkg, plid, type, BLKIO_STAT_READ) +
|
||||
blkio_read_stat_cpu(blkg, plid, type, BLKIO_STAT_WRITE);
|
||||
disk_total = blkio_read_stat_cpu(blkg, plid, type, BLKG_RWSTAT_READ) +
|
||||
blkio_read_stat_cpu(blkg, plid, type, BLKG_RWSTAT_WRITE);
|
||||
|
||||
blkio_get_key_name(BLKIO_STAT_TOTAL, dname, key_str, MAX_KEY_LEN,
|
||||
blkio_get_key_name(BLKG_RWSTAT_TOTAL, dname, key_str, MAX_KEY_LEN,
|
||||
false);
|
||||
cb->fill(cb, key_str, disk_total);
|
||||
return disk_total;
|
||||
@ -905,65 +859,76 @@ static uint64_t blkio_get_stat(struct blkio_group *blkg, int plid,
|
||||
struct blkio_group_stats *stats = &blkg->pd[plid]->stats;
|
||||
uint64_t v = 0, disk_total = 0;
|
||||
char key_str[MAX_KEY_LEN];
|
||||
unsigned int sync_start;
|
||||
struct blkg_rwstat rws = { };
|
||||
int st;
|
||||
|
||||
if (type >= BLKIO_STAT_ARR_NR) {
|
||||
do {
|
||||
sync_start = u64_stats_fetch_begin(&stats->syncp);
|
||||
switch (type) {
|
||||
case BLKIO_STAT_TIME:
|
||||
v = stats->time;
|
||||
break;
|
||||
switch (type) {
|
||||
case BLKIO_STAT_TIME:
|
||||
v = blkg_stat_read(&stats->time);
|
||||
break;
|
||||
#ifdef CONFIG_DEBUG_BLK_CGROUP
|
||||
case BLKIO_STAT_UNACCOUNTED_TIME:
|
||||
v = stats->unaccounted_time;
|
||||
break;
|
||||
case BLKIO_STAT_AVG_QUEUE_SIZE: {
|
||||
uint64_t samples = stats->avg_queue_size_samples;
|
||||
case BLKIO_STAT_UNACCOUNTED_TIME:
|
||||
v = blkg_stat_read(&stats->unaccounted_time);
|
||||
break;
|
||||
case BLKIO_STAT_AVG_QUEUE_SIZE: {
|
||||
uint64_t samples;
|
||||
|
||||
if (samples) {
|
||||
v = stats->avg_queue_size_sum;
|
||||
do_div(v, samples);
|
||||
}
|
||||
break;
|
||||
samples = blkg_stat_read(&stats->avg_queue_size_samples);
|
||||
if (samples) {
|
||||
v = blkg_stat_read(&stats->avg_queue_size_sum);
|
||||
do_div(v, samples);
|
||||
}
|
||||
case BLKIO_STAT_IDLE_TIME:
|
||||
v = stats->idle_time;
|
||||
break;
|
||||
case BLKIO_STAT_EMPTY_TIME:
|
||||
v = stats->empty_time;
|
||||
break;
|
||||
case BLKIO_STAT_DEQUEUE:
|
||||
v = stats->dequeue;
|
||||
break;
|
||||
case BLKIO_STAT_GROUP_WAIT_TIME:
|
||||
v = stats->group_wait_time;
|
||||
break;
|
||||
break;
|
||||
}
|
||||
case BLKIO_STAT_IDLE_TIME:
|
||||
v = blkg_stat_read(&stats->idle_time);
|
||||
break;
|
||||
case BLKIO_STAT_EMPTY_TIME:
|
||||
v = blkg_stat_read(&stats->empty_time);
|
||||
break;
|
||||
case BLKIO_STAT_DEQUEUE:
|
||||
v = blkg_stat_read(&stats->dequeue);
|
||||
break;
|
||||
case BLKIO_STAT_GROUP_WAIT_TIME:
|
||||
v = blkg_stat_read(&stats->group_wait_time);
|
||||
break;
|
||||
#endif
|
||||
default:
|
||||
WARN_ON_ONCE(1);
|
||||
}
|
||||
} while (u64_stats_fetch_retry(&stats->syncp, sync_start));
|
||||
default:
|
||||
WARN_ON_ONCE(1);
|
||||
}
|
||||
|
||||
blkio_get_key_name(0, dname, key_str, MAX_KEY_LEN, true);
|
||||
cb->fill(cb, key_str, v);
|
||||
return v;
|
||||
}
|
||||
|
||||
for (st = BLKIO_STAT_READ; st < BLKIO_STAT_TOTAL; st++) {
|
||||
do {
|
||||
sync_start = u64_stats_fetch_begin(&stats->syncp);
|
||||
v = stats->stat_arr[type][st];
|
||||
} while (u64_stats_fetch_retry(&stats->syncp, sync_start));
|
||||
|
||||
blkio_get_key_name(st, dname, key_str, MAX_KEY_LEN, false);
|
||||
cb->fill(cb, key_str, v);
|
||||
if (st == BLKIO_STAT_READ || st == BLKIO_STAT_WRITE)
|
||||
disk_total += v;
|
||||
switch (type) {
|
||||
case BLKIO_STAT_MERGED:
|
||||
rws = blkg_rwstat_read(&stats->merged);
|
||||
break;
|
||||
case BLKIO_STAT_SERVICE_TIME:
|
||||
rws = blkg_rwstat_read(&stats->service_time);
|
||||
break;
|
||||
case BLKIO_STAT_WAIT_TIME:
|
||||
rws = blkg_rwstat_read(&stats->wait_time);
|
||||
break;
|
||||
case BLKIO_STAT_QUEUED:
|
||||
rws = blkg_rwstat_read(&stats->queued);
|
||||
break;
|
||||
default:
|
||||
WARN_ON_ONCE(true);
|
||||
break;
|
||||
}
|
||||
|
||||
blkio_get_key_name(BLKIO_STAT_TOTAL, dname, key_str, MAX_KEY_LEN,
|
||||
for (st = BLKG_RWSTAT_READ; st < BLKG_RWSTAT_NR; st++) {
|
||||
blkio_get_key_name(st, dname, key_str, MAX_KEY_LEN, false);
|
||||
cb->fill(cb, key_str, rws.cnt[st]);
|
||||
if (st == BLKG_RWSTAT_READ || st == BLKG_RWSTAT_WRITE)
|
||||
disk_total += rws.cnt[st];
|
||||
}
|
||||
|
||||
blkio_get_key_name(BLKG_RWSTAT_TOTAL, dname, key_str, MAX_KEY_LEN,
|
||||
false);
|
||||
cb->fill(cb, key_str, disk_total);
|
||||
return disk_total;
|
||||
|
||||
@ -69,12 +69,14 @@ enum stat_type_cpu {
|
||||
|
||||
#define BLKIO_STAT_CPU_ARR_NR (BLKIO_STAT_CPU_SERVICED + 1)
|
||||
|
||||
enum stat_sub_type {
|
||||
BLKIO_STAT_READ = 0,
|
||||
BLKIO_STAT_WRITE,
|
||||
BLKIO_STAT_SYNC,
|
||||
BLKIO_STAT_ASYNC,
|
||||
BLKIO_STAT_TOTAL
|
||||
enum blkg_rwstat_type {
|
||||
BLKG_RWSTAT_READ,
|
||||
BLKG_RWSTAT_WRITE,
|
||||
BLKG_RWSTAT_SYNC,
|
||||
BLKG_RWSTAT_ASYNC,
|
||||
|
||||
BLKG_RWSTAT_NR,
|
||||
BLKG_RWSTAT_TOTAL = BLKG_RWSTAT_NR,
|
||||
};
|
||||
|
||||
/* blkg state flags */
|
||||
@ -124,54 +126,58 @@ struct blkio_cgroup {
|
||||
uint64_t id;
|
||||
};
|
||||
|
||||
struct blkg_stat {
|
||||
struct u64_stats_sync syncp;
|
||||
uint64_t cnt;
|
||||
};
|
||||
|
||||
struct blkg_rwstat {
|
||||
struct u64_stats_sync syncp;
|
||||
uint64_t cnt[BLKG_RWSTAT_NR];
|
||||
};
|
||||
|
||||
struct blkio_group_stats {
|
||||
struct u64_stats_sync syncp;
|
||||
/* number of ios merged */
|
||||
struct blkg_rwstat merged;
|
||||
/* total time spent on device in ns, may not be accurate w/ queueing */
|
||||
struct blkg_rwstat service_time;
|
||||
/* total time spent waiting in scheduler queue in ns */
|
||||
struct blkg_rwstat wait_time;
|
||||
/* number of IOs queued up */
|
||||
struct blkg_rwstat queued;
|
||||
/* total disk time and nr sectors dispatched by this group */
|
||||
uint64_t time;
|
||||
uint64_t stat_arr[BLKIO_STAT_ARR_NR][BLKIO_STAT_TOTAL];
|
||||
struct blkg_stat time;
|
||||
#ifdef CONFIG_DEBUG_BLK_CGROUP
|
||||
/* Time not charged to this cgroup */
|
||||
uint64_t unaccounted_time;
|
||||
|
||||
/* Sum of number of IOs queued across all samples */
|
||||
uint64_t avg_queue_size_sum;
|
||||
/* Count of samples taken for average */
|
||||
uint64_t avg_queue_size_samples;
|
||||
/* How many times this group has been removed from service tree */
|
||||
unsigned long dequeue;
|
||||
|
||||
/* Total time spent waiting for it to be assigned a timeslice. */
|
||||
uint64_t group_wait_time;
|
||||
|
||||
/* Time spent idling for this blkio_group */
|
||||
uint64_t idle_time;
|
||||
/*
|
||||
* Total time when we have requests queued and do not contain the
|
||||
* current active queue.
|
||||
*/
|
||||
uint64_t empty_time;
|
||||
|
||||
/* time not charged to this cgroup */
|
||||
struct blkg_stat unaccounted_time;
|
||||
/* sum of number of ios queued across all samples */
|
||||
struct blkg_stat avg_queue_size_sum;
|
||||
/* count of samples taken for average */
|
||||
struct blkg_stat avg_queue_size_samples;
|
||||
/* how many times this group has been removed from service tree */
|
||||
struct blkg_stat dequeue;
|
||||
/* total time spent waiting for it to be assigned a timeslice. */
|
||||
struct blkg_stat group_wait_time;
|
||||
/* time spent idling for this blkio_group */
|
||||
struct blkg_stat idle_time;
|
||||
/* total time with empty current active q with other requests queued */
|
||||
struct blkg_stat empty_time;
|
||||
/* fields after this shouldn't be cleared on stat reset */
|
||||
uint64_t start_group_wait_time;
|
||||
uint64_t start_idle_time;
|
||||
uint64_t start_empty_time;
|
||||
uint16_t flags;
|
||||
uint64_t start_group_wait_time;
|
||||
uint64_t start_idle_time;
|
||||
uint64_t start_empty_time;
|
||||
uint16_t flags;
|
||||
#endif
|
||||
};
|
||||
|
||||
#ifdef CONFIG_DEBUG_BLK_CGROUP
|
||||
#define BLKG_STATS_DEBUG_CLEAR_START \
|
||||
offsetof(struct blkio_group_stats, unaccounted_time)
|
||||
#define BLKG_STATS_DEBUG_CLEAR_SIZE \
|
||||
(offsetof(struct blkio_group_stats, start_group_wait_time) - \
|
||||
BLKG_STATS_DEBUG_CLEAR_START)
|
||||
#endif
|
||||
|
||||
/* Per cpu blkio group stats */
|
||||
struct blkio_group_stats_cpu {
|
||||
uint64_t sectors;
|
||||
uint64_t stat_arr_cpu[BLKIO_STAT_CPU_ARR_NR][BLKIO_STAT_TOTAL];
|
||||
struct u64_stats_sync syncp;
|
||||
/* total bytes transferred */
|
||||
struct blkg_rwstat service_bytes;
|
||||
/* total IOs serviced, post merge */
|
||||
struct blkg_rwstat serviced;
|
||||
/* total sectors transferred */
|
||||
struct blkg_stat sectors;
|
||||
};
|
||||
|
||||
struct blkio_group_conf {
|
||||
@ -316,6 +322,121 @@ static inline void blkg_put(struct blkio_group *blkg)
|
||||
__blkg_release(blkg);
|
||||
}
|
||||
|
||||
/**
|
||||
* blkg_stat_add - add a value to a blkg_stat
|
||||
* @stat: target blkg_stat
|
||||
* @val: value to add
|
||||
*
|
||||
* Add @val to @stat. The caller is responsible for synchronizing calls to
|
||||
* this function.
|
||||
*/
|
||||
static inline void blkg_stat_add(struct blkg_stat *stat, uint64_t val)
|
||||
{
|
||||
u64_stats_update_begin(&stat->syncp);
|
||||
stat->cnt += val;
|
||||
u64_stats_update_end(&stat->syncp);
|
||||
}
|
||||
|
||||
/**
|
||||
* blkg_stat_read - read the current value of a blkg_stat
|
||||
* @stat: blkg_stat to read
|
||||
*
|
||||
* Read the current value of @stat. This function can be called without
|
||||
* synchroniztion and takes care of u64 atomicity.
|
||||
*/
|
||||
static inline uint64_t blkg_stat_read(struct blkg_stat *stat)
|
||||
{
|
||||
unsigned int start;
|
||||
uint64_t v;
|
||||
|
||||
do {
|
||||
start = u64_stats_fetch_begin(&stat->syncp);
|
||||
v = stat->cnt;
|
||||
} while (u64_stats_fetch_retry(&stat->syncp, start));
|
||||
|
||||
return v;
|
||||
}
|
||||
|
||||
/**
|
||||
* blkg_stat_reset - reset a blkg_stat
|
||||
* @stat: blkg_stat to reset
|
||||
*/
|
||||
static inline void blkg_stat_reset(struct blkg_stat *stat)
|
||||
{
|
||||
stat->cnt = 0;
|
||||
}
|
||||
|
||||
/**
|
||||
* blkg_rwstat_add - add a value to a blkg_rwstat
|
||||
* @rwstat: target blkg_rwstat
|
||||
* @rw: mask of REQ_{WRITE|SYNC}
|
||||
* @val: value to add
|
||||
*
|
||||
* Add @val to @rwstat. The counters are chosen according to @rw. The
|
||||
* caller is responsible for synchronizing calls to this function.
|
||||
*/
|
||||
static inline void blkg_rwstat_add(struct blkg_rwstat *rwstat,
|
||||
int rw, uint64_t val)
|
||||
{
|
||||
u64_stats_update_begin(&rwstat->syncp);
|
||||
|
||||
if (rw & REQ_WRITE)
|
||||
rwstat->cnt[BLKG_RWSTAT_WRITE] += val;
|
||||
else
|
||||
rwstat->cnt[BLKG_RWSTAT_READ] += val;
|
||||
if (rw & REQ_SYNC)
|
||||
rwstat->cnt[BLKG_RWSTAT_SYNC] += val;
|
||||
else
|
||||
rwstat->cnt[BLKG_RWSTAT_ASYNC] += val;
|
||||
|
||||
u64_stats_update_end(&rwstat->syncp);
|
||||
}
|
||||
|
||||
/**
|
||||
* blkg_rwstat_read - read the current values of a blkg_rwstat
|
||||
* @rwstat: blkg_rwstat to read
|
||||
*
|
||||
* Read the current snapshot of @rwstat and return it as the return value.
|
||||
* This function can be called without synchronization and takes care of
|
||||
* u64 atomicity.
|
||||
*/
|
||||
static struct blkg_rwstat blkg_rwstat_read(struct blkg_rwstat *rwstat)
|
||||
{
|
||||
unsigned int start;
|
||||
struct blkg_rwstat tmp;
|
||||
|
||||
do {
|
||||
start = u64_stats_fetch_begin(&rwstat->syncp);
|
||||
tmp = *rwstat;
|
||||
} while (u64_stats_fetch_retry(&rwstat->syncp, start));
|
||||
|
||||
return tmp;
|
||||
}
|
||||
|
||||
/**
|
||||
* blkg_rwstat_sum - read the total count of a blkg_rwstat
|
||||
* @rwstat: blkg_rwstat to read
|
||||
*
|
||||
* Return the total count of @rwstat regardless of the IO direction. This
|
||||
* function can be called without synchronization and takes care of u64
|
||||
* atomicity.
|
||||
*/
|
||||
static inline uint64_t blkg_rwstat_sum(struct blkg_rwstat *rwstat)
|
||||
{
|
||||
struct blkg_rwstat tmp = blkg_rwstat_read(rwstat);
|
||||
|
||||
return tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE];
|
||||
}
|
||||
|
||||
/**
|
||||
* blkg_rwstat_reset - reset a blkg_rwstat
|
||||
* @rwstat: blkg_rwstat to reset
|
||||
*/
|
||||
static inline void blkg_rwstat_reset(struct blkg_rwstat *rwstat)
|
||||
{
|
||||
memset(rwstat->cnt, 0, sizeof(rwstat->cnt));
|
||||
}
|
||||
|
||||
#else
|
||||
|
||||
struct blkio_group {
|
||||
|
||||
Loading…
Reference in New Issue
Block a user