From 84c7afcebed913c93d50f116b046b7f0d8ec0cdc Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Wed, 9 May 2018 02:08:51 -0700 Subject: block: use ktime_get_ns() instead of sched_clock() for cfq and bfq cfq and bfq have some internal fields that use sched_clock() which can trivially use ktime_get_ns() instead. Their timestamp fields in struct request can also use ktime_get_ns(), which resolves the 8 year old comment added by commit 28f4197e5d47 ("block: disable preemption before using sched_clock()"). Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe --- block/cfq-iosched.c | 49 ++++++++++++++++++++++++++----------------------- 1 file changed, 26 insertions(+), 23 deletions(-) (limited to 'block/cfq-iosched.c') diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 9f342ef1ad426..652ca064de206 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -210,9 +210,9 @@ struct cfqg_stats { /* 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; + u64 start_group_wait_time; + u64 start_idle_time; + u64 start_empty_time; uint16_t flags; #endif /* CONFIG_DEBUG_BLK_CGROUP */ #endif /* CONFIG_CFQ_GROUP_IOSCHED */ @@ -491,13 +491,13 @@ CFQG_FLAG_FNS(empty) /* This should be called with the queue_lock held. */ static void cfqg_stats_update_group_wait_time(struct cfqg_stats *stats) { - unsigned long long now; + u64 now; if (!cfqg_stats_waiting(stats)) return; - now = sched_clock(); - if (time_after64(now, stats->start_group_wait_time)) + now = ktime_get_ns(); + if (now > stats->start_group_wait_time) blkg_stat_add(&stats->group_wait_time, now - stats->start_group_wait_time); cfqg_stats_clear_waiting(stats); @@ -513,20 +513,20 @@ static void cfqg_stats_set_start_group_wait_time(struct cfq_group *cfqg, return; if (cfqg == curr_cfqg) return; - stats->start_group_wait_time = sched_clock(); + stats->start_group_wait_time = ktime_get_ns(); cfqg_stats_mark_waiting(stats); } /* This should be called with the queue_lock held. */ static void cfqg_stats_end_empty_time(struct cfqg_stats *stats) { - unsigned long long now; + u64 now; if (!cfqg_stats_empty(stats)) return; - now = sched_clock(); - if (time_after64(now, stats->start_empty_time)) + now = ktime_get_ns(); + if (now > stats->start_empty_time) blkg_stat_add(&stats->empty_time, now - stats->start_empty_time); cfqg_stats_clear_empty(stats); @@ -552,7 +552,7 @@ static void cfqg_stats_set_start_empty_time(struct cfq_group *cfqg) if (cfqg_stats_empty(stats)) return; - stats->start_empty_time = sched_clock(); + stats->start_empty_time = ktime_get_ns(); cfqg_stats_mark_empty(stats); } @@ -561,9 +561,9 @@ static void cfqg_stats_update_idle_time(struct cfq_group *cfqg) struct cfqg_stats *stats = &cfqg->stats; if (cfqg_stats_idling(stats)) { - unsigned long long now = sched_clock(); + u64 now = ktime_get_ns(); - if (time_after64(now, stats->start_idle_time)) + if (now > stats->start_idle_time) blkg_stat_add(&stats->idle_time, now - stats->start_idle_time); cfqg_stats_clear_idling(stats); @@ -576,7 +576,7 @@ static void cfqg_stats_set_start_idle_time(struct cfq_group *cfqg) BUG_ON(cfqg_stats_idling(stats)); - stats->start_idle_time = sched_clock(); + stats->start_idle_time = ktime_get_ns(); cfqg_stats_mark_idling(stats); } @@ -701,17 +701,19 @@ static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, } static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, - uint64_t start_time, uint64_t io_start_time, - unsigned int op) + u64 start_time_ns, + u64 io_start_time_ns, + unsigned int op) { struct cfqg_stats *stats = &cfqg->stats; - unsigned long long now = sched_clock(); + u64 now = ktime_get_ns(); - if (time_after64(now, io_start_time)) - blkg_rwstat_add(&stats->service_time, op, now - io_start_time); - if (time_after64(io_start_time, start_time)) + if (now > io_start_time_ns) + blkg_rwstat_add(&stats->service_time, op, + now - io_start_time_ns); + if (io_start_time_ns > start_time_ns) blkg_rwstat_add(&stats->wait_time, op, - io_start_time - start_time); + io_start_time_ns - start_time_ns); } /* @stats = 0 */ @@ -797,8 +799,9 @@ static inline void cfqg_stats_update_io_remove(struct cfq_group *cfqg, static inline void cfqg_stats_update_io_merged(struct cfq_group *cfqg, unsigned int op) { } static inline void cfqg_stats_update_completion(struct cfq_group *cfqg, - uint64_t start_time, uint64_t io_start_time, - unsigned int op) { } + u64 start_time_ns, + u64 io_start_time_ns, + unsigned int op) { } #endif /* CONFIG_CFQ_GROUP_IOSCHED */ -- cgit v1.2.3