diff options
| author | Connor O'Brien <connoro@google.com> | 2017-05-19 12:36:17 -0700 |
|---|---|---|
| committer | Georg Veichtlbauer <georg@vware.at> | 2023-07-26 21:01:08 +0200 |
| commit | e280a059986f9185bdcfde732fcf65edac321d47 (patch) | |
| tree | c5d98637902c7a6f3de4fea2d7c5ed8fd4859bd3 | |
| parent | f39d0b496aa4e13cbcf23bdf3c22d356bd783b9e (diff) | |
sched/tune: allow negative cpu boosts
schedtune sets 0 as the floor for calculating CPU max boost, so
negative schedtune.boost values do not affect CPU frequency
decisions. Remove this restriction to allow userspace to apply
negative boosts when appropriate.
Also change treatment of the root boost group to match the other
groups, so it only affects the CPU boost if it has runnable tasks on
the CPU.
Test: set all boosts negative; sched_boost_cpu trace events show
negative CPU margins.
Change-Id: I89f3470299aef96a18797c105f02ebc8f367b5e1
Signed-off-by: Connor O'Brien <connoro@google.com>
| -rw-r--r-- | kernel/sched/tune.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/kernel/sched/tune.c b/kernel/sched/tune.c index 62d7a0f93cef..f8c4e29763d3 100644 --- a/kernel/sched/tune.c +++ b/kernel/sched/tune.c @@ -392,14 +392,12 @@ static void schedtune_cpu_update(int cpu) { struct boost_groups *bg; - int boost_max; + int boost_max = INT_MIN; 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) { + for (idx = 0; idx < BOOSTGROUPS_COUNT; ++idx) { /* * A boost group affects a CPU only if it has * RUNNABLE tasks on that CPU @@ -409,10 +407,10 @@ schedtune_cpu_update(int cpu) boost_max = max(boost_max, bg->group[idx].boost); } - /* Ensures boost_max is non-negative when all cgroup boost values - * are neagtive. Avoids under-accounting of cpu capacity which may cause - * task stacking and frequency spikes.*/ - boost_max = max(boost_max, 0); + + /* If there are no active boost groups on the CPU, set no boost */ + if (boost_max == INT_MIN) + boost_max = 0; bg->boost_max = boost_max; } |