diff options
| -rw-r--r-- | kernel/sched/tune.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/kernel/sched/tune.c b/kernel/sched/tune.c index 95bc8b87c6d4..f62386893725 100644 --- a/kernel/sched/tune.c +++ b/kernel/sched/tune.c @@ -97,6 +97,67 @@ struct boost_groups { /* Boost groups affecting each CPU in the system */ DEFINE_PER_CPU(struct boost_groups, cpu_boost_groups); +static void +schedtune_cpu_update(int cpu) +{ + struct boost_groups *bg; + unsigned boost_max; + int idx; + + bg = &per_cpu(cpu_boost_groups, cpu); + + /* The root boost group is always active */ + boost_max = bg->group[0].boost; + for (idx = 1; idx < BOOSTGROUPS_COUNT; ++idx) { + /* + * A boost group affects a CPU only if it has + * RUNNABLE tasks on that CPU + */ + if (bg->group[idx].tasks == 0) + continue; + boost_max = max(boost_max, bg->group[idx].boost); + } + + bg->boost_max = boost_max; +} + +static int +schedtune_boostgroup_update(int idx, int boost) +{ + struct boost_groups *bg; + int cur_boost_max; + int old_boost; + int cpu; + + /* Update per CPU boost groups */ + for_each_possible_cpu(cpu) { + bg = &per_cpu(cpu_boost_groups, cpu); + + /* + * Keep track of current boost values to compute the per CPU + * maximum only when it has been affected by the new value of + * the updated boost group + */ + cur_boost_max = bg->boost_max; + old_boost = bg->group[idx].boost; + + /* Update the boost value of this boost group */ + bg->group[idx].boost = boost; + + /* Check if this update increase current max */ + if (boost > cur_boost_max && bg->group[idx].tasks) { + bg->boost_max = boost; + continue; + } + + /* Check if this update has decreased current max */ + if (cur_boost_max == old_boost && old_boost > boost) + schedtune_cpu_update(cpu); + } + + return 0; +} + static u64 boost_read(struct cgroup_subsys_state *css, struct cftype *cft) { @@ -118,6 +179,9 @@ boost_write(struct cgroup_subsys_state *css, struct cftype *cft, if (css == &root_schedtune.css) sysctl_sched_cfs_boost = boost; + /* Update CPU boost */ + schedtune_boostgroup_update(st->idx, st->boost); + return 0; } @@ -133,9 +197,19 @@ static struct cftype files[] = { static int schedtune_boostgroup_init(struct schedtune *st) { + struct boost_groups *bg; + int cpu; + /* Keep track of allocated boost groups */ allocated_group[st->idx] = st; + /* Initialize the per CPU boost groups */ + for_each_possible_cpu(cpu) { + bg = &per_cpu(cpu_boost_groups, cpu); + bg->group[st->idx].boost = 0; + bg->group[st->idx].tasks = 0; + } + return 0; } @@ -203,6 +277,9 @@ out: static void schedtune_boostgroup_release(struct schedtune *st) { + /* Reset this boost group */ + schedtune_boostgroup_update(st->idx, 0); + /* Keep track of allocated boost groups */ allocated_group[st->idx] = NULL; } |