On Mon, Dec 18, 2023 at 1:59 AM Qais Yousef <qyousef@xxxxxxxxxxx> wrote:
On 11/29/23 11:08, Lukasz Luba wrote:
The new Energy Model (EM) supports runtime modification of the performance
state table to better model the power used by the SoC. Use this new
feature to improve energy estimation and therefore task placement in
Energy Aware Scheduler (EAS).
nit: you moved the code to use the new runtime em table instead of the one
parsed at boot.
Signed-off-by: Lukasz Luba <lukasz.luba@xxxxxxx>
---
include/linux/energy_model.h | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
index 1e618e431cac..94a77a813724 100644
--- a/include/linux/energy_model.h
+++ b/include/linux/energy_model.h
@@ -238,6 +238,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
unsigned long max_util, unsigned long sum_util,
unsigned long allowed_cpu_cap)
{
+ struct em_perf_table *runtime_table;
unsigned long freq, scale_cpu;
struct em_perf_state *ps;
int cpu, i;
@@ -255,7 +256,14 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
*/
cpu = cpumask_first(to_cpumask(pd->cpus));
scale_cpu = arch_scale_cpu_capacity(cpu);
- ps = &pd->table[pd->nr_perf_states - 1];
+
+ /*
+ * No rcu_read_lock() since it's already called by task scheduler.
+ * The runtime_table is always there for CPUs, so we don't check.
+ */
WARN_ON(rcu_read_lock_held()) instead?
I agree, or SCHED_WARN_ON(!rcu_read_lock_held()) ?