diff options
Diffstat (limited to 'kernel/sched/cpufreq_schedutil.c')
| -rw-r--r-- | kernel/sched/cpufreq_schedutil.c | 72 |
1 files changed, 32 insertions, 40 deletions
diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c index 2efe629425be..962cf343f798 100644 --- a/kernel/sched/cpufreq_schedutil.c +++ b/kernel/sched/cpufreq_schedutil.c @@ -13,6 +13,8 @@ #include <linux/sched/cpufreq.h> #include <trace/events/power.h> +#define IOWAIT_BOOST_MIN (SCHED_CAPACITY_SCALE / 8) + struct sugov_tunables { struct gov_attr_set attr_set; unsigned int rate_limit_us; @@ -48,7 +50,6 @@ struct sugov_cpu { bool iowait_boost_pending; unsigned int iowait_boost; - unsigned int iowait_boost_max; u64 last_update; unsigned long bw_dl; @@ -291,8 +292,8 @@ static unsigned long sugov_get_util(struct sugov_cpu *sg_cpu) * * The IO wait boost of a task is disabled after a tick since the last update * of a CPU. If a new IO wait boost is requested after more then a tick, then - * we enable the boost starting from the minimum frequency, which improves - * energy efficiency by ignoring sporadic wakeups from IO. + * we enable the boost starting from IOWAIT_BOOST_MIN, which improves energy + * efficiency by ignoring sporadic wakeups from IO. */ static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time, bool set_iowait_boost) @@ -303,8 +304,7 @@ static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time, if (delta_ns <= TICK_NSEC) return false; - sg_cpu->iowait_boost = set_iowait_boost - ? sg_cpu->sg_policy->policy->min : 0; + sg_cpu->iowait_boost = set_iowait_boost ? IOWAIT_BOOST_MIN : 0; sg_cpu->iowait_boost_pending = set_iowait_boost; return true; @@ -318,8 +318,9 @@ static bool sugov_iowait_reset(struct sugov_cpu *sg_cpu, u64 time, * * Each time a task wakes up after an IO operation, the CPU utilization can be * boosted to a certain utilization which doubles at each "frequent and - * successive" wakeup from IO, ranging from the utilization of the minimum - * OPP to the utilization of the maximum OPP. + * successive" wakeup from IO, ranging from IOWAIT_BOOST_MIN to the utilization + * of the maximum OPP. + * * To keep doubling, an IO boost has to be requested at least once per tick, * otherwise we restart from the utilization of the minimum OPP. */ @@ -344,14 +345,13 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, /* Double the boost at each request */ if (sg_cpu->iowait_boost) { - sg_cpu->iowait_boost <<= 1; - if (sg_cpu->iowait_boost > sg_cpu->iowait_boost_max) - sg_cpu->iowait_boost = sg_cpu->iowait_boost_max; + sg_cpu->iowait_boost = + min_t(unsigned int, sg_cpu->iowait_boost << 1, SCHED_CAPACITY_SCALE); return; } /* First wakeup after IO: start with minimum boost */ - sg_cpu->iowait_boost = sg_cpu->sg_policy->policy->min; + sg_cpu->iowait_boost = IOWAIT_BOOST_MIN; } /** @@ -373,47 +373,38 @@ static void sugov_iowait_boost(struct sugov_cpu *sg_cpu, u64 time, * This mechanism is designed to boost high frequently IO waiting tasks, while * being more conservative on tasks which does sporadic IO operations. */ -static void sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, - unsigned long *util, unsigned long *max) +static unsigned long sugov_iowait_apply(struct sugov_cpu *sg_cpu, u64 time, + unsigned long util, unsigned long max) { - unsigned int boost_util, boost_max; + unsigned long boost; /* No boost currently required */ if (!sg_cpu->iowait_boost) - return; + return util; /* Reset boost if the CPU appears to have been idle enough */ if (sugov_iowait_reset(sg_cpu, time, false)) - return; + return util; - /* - * An IO waiting task has just woken up: - * allow to further double the boost value - */ - if (sg_cpu->iowait_boost_pending) { - sg_cpu->iowait_boost_pending = false; - } else { + if (!sg_cpu->iowait_boost_pending) { /* - * Otherwise: reduce the boost value and disable it when we - * reach the minimum. + * No boost pending; reduce the boost value. */ sg_cpu->iowait_boost >>= 1; - if (sg_cpu->iowait_boost < sg_cpu->sg_policy->policy->min) { + if (sg_cpu->iowait_boost < IOWAIT_BOOST_MIN) { sg_cpu->iowait_boost = 0; - return; + return util; } } + sg_cpu->iowait_boost_pending = false; + /* - * Apply the current boost value: a CPU is boosted only if its current - * utilization is smaller then the current IO boost level. + * @util is already in capacity scale; convert iowait_boost + * into the same scale so we can compare. */ - boost_util = sg_cpu->iowait_boost; - boost_max = sg_cpu->iowait_boost_max; - if (*util * boost_max < *max * boost_util) { - *util = boost_util; - *max = boost_max; - } + boost = (sg_cpu->iowait_boost * max) >> SCHED_CAPACITY_SHIFT; + return max(boost, util); } #ifdef CONFIG_NO_HZ_COMMON @@ -460,7 +451,7 @@ static void sugov_update_single(struct update_util_data *hook, u64 time, util = sugov_get_util(sg_cpu); max = sg_cpu->max; - sugov_iowait_apply(sg_cpu, time, &util, &max); + util = sugov_iowait_apply(sg_cpu, time, util, max); next_f = get_next_freq(sg_policy, util, max); /* * Do not reduce the frequency if the CPU has not been idle @@ -500,7 +491,7 @@ static unsigned int sugov_next_freq_shared(struct sugov_cpu *sg_cpu, u64 time) j_util = sugov_get_util(j_sg_cpu); j_max = j_sg_cpu->max; - sugov_iowait_apply(j_sg_cpu, time, &j_util, &j_max); + j_util = sugov_iowait_apply(j_sg_cpu, time, j_util, j_max); if (j_util * max > j_max * util) { util = j_util; @@ -609,13 +600,14 @@ rate_limit_us_store(struct gov_attr_set *attr_set, const char *buf, size_t count static struct governor_attr rate_limit_us = __ATTR_RW(rate_limit_us); -static struct attribute *sugov_attributes[] = { +static struct attribute *sugov_attrs[] = { &rate_limit_us.attr, NULL }; +ATTRIBUTE_GROUPS(sugov); static struct kobj_type sugov_tunables_ktype = { - .default_attrs = sugov_attributes, + .default_groups = sugov_groups, .sysfs_ops = &governor_sysfs_ops, }; @@ -782,6 +774,7 @@ out: return 0; fail: + kobject_put(&tunables->attr_set.kobj); policy->governor_data = NULL; sugov_tunables_free(tunables); @@ -837,7 +830,6 @@ static int sugov_start(struct cpufreq_policy *policy) memset(sg_cpu, 0, sizeof(*sg_cpu)); sg_cpu->cpu = cpu; sg_cpu->sg_policy = sg_policy; - sg_cpu->iowait_boost_max = policy->cpuinfo.max_freq; } for_each_cpu(cpu, policy->cpus) { |