diff options
| author | Varun Wadekar <vwadekar@nvidia.com> | 2012-05-07 15:12:25 -0700 |
|---|---|---|
| committer | Dan Willemsen <dwillemsen@nvidia.com> | 2013-09-14 12:13:16 -0700 |
| commit | e23fd0bf7e184cb10624d5df433afc9d2cc48930 (patch) | |
| tree | b3cd8599f23efa61feb1dc342ef0e9190a0fca67 /kernel/sched | |
| parent | 10bb490f7b86028941f688cfe0670824e2d80cd1 (diff) | |
scheduler: compute time-average nr_running per run-queue
Port commit 0b5a8a6f3 (http://git-master/r/111635) from v3.1
Compute the time-average number of running tasks per run-queue for a
trailing window of a fixed time period. The delta add/sub to the
average value is weighted by the amount of time per nr_running value
relative to the total measurement period.
Original author: Diwakar Tundlam <dtundlam@nvidia.com>
Change-Id: I076e24ff4ed65bed3b8dd8d2b279a503318071ff
Signed-off-by: Diwakar Tundlam <dtundlam@nvidia.com>
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
Rebase-Id: R1760349117674c9cf5ea63046f937a7c7a0186f6
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/debug.c | 3 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 41 |
2 files changed, 44 insertions, 0 deletions
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 75024a673520..ad1b66c36096 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -281,6 +281,9 @@ do { \ SEQ_printf(m, " .%-30s: %Ld.%06ld\n", #x, SPLIT_NS(rq->x)) P(nr_running); + SEQ_printf(m, " .%-30s: %d.%03d \n", "ave_nr_running", + rq->ave_nr_running / FIXED_1, + ((rq->ave_nr_running % FIXED_1) * 1000) / FIXED_1); SEQ_printf(m, " .%-30s: %lu\n", "load", rq->load.weight); P(nr_switches); diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index ce39224d6155..aa12450076cd 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -415,6 +415,10 @@ struct rq { #endif int skip_clock_update; + /* time-based average load */ + u64 nr_last_stamp; + unsigned int ave_nr_running; + /* capture load from *all* tasks on this cpu: */ struct load_weight load; unsigned long nr_load_updates; @@ -1073,8 +1077,34 @@ static inline u64 steal_ticks(u64 steal) } #endif +/* 27 ~= 134217728ns = 134.2ms + * 26 ~= 67108864ns = 67.1ms + * 25 ~= 33554432ns = 33.5ms + * 24 ~= 16777216ns = 16.8ms + */ +#define NR_AVE_PERIOD_EXP 27 +#define NR_AVE_SCALE(x) ((x) << FSHIFT) +#define NR_AVE_PERIOD (1 << NR_AVE_PERIOD_EXP) +#define NR_AVE_DIV_PERIOD(x) ((x) >> NR_AVE_PERIOD_EXP) + +static inline void do_avg_nr_running(struct rq *rq) +{ + s64 nr, deltax; + + deltax = rq->clock_task - rq->nr_last_stamp; + rq->nr_last_stamp = rq->clock_task; + nr = NR_AVE_SCALE(rq->nr_running); + + if (deltax > NR_AVE_PERIOD) + rq->ave_nr_running = nr; + else + rq->ave_nr_running += + NR_AVE_DIV_PERIOD(deltax * (nr - rq->ave_nr_running)); +} + static inline void inc_nr_running(struct rq *rq) { + do_avg_nr_running(rq); rq->nr_running++; #ifdef CONFIG_NO_HZ_FULL @@ -1090,9 +1120,20 @@ static inline void inc_nr_running(struct rq *rq) static inline void dec_nr_running(struct rq *rq) { + do_avg_nr_running(rq); rq->nr_running--; } +unsigned long avg_nr_running(void) +{ + unsigned long i, sum = 0; + + for_each_online_cpu(i) + sum += cpu_rq(i)->ave_nr_running; + + return sum; +} + static inline void rq_last_tick_reset(struct rq *rq) { #ifdef CONFIG_NO_HZ_FULL |