diff mbox series

[RESEND,v2,2/4] PM: EM: Change the em_adjust_new_capacity() to re-use code

Message ID 20240322110850.77086-3-lukasz.luba@arm.com
State Superseded
Headers show
Series Update Energy Model after chip binning adjusted voltages | expand

Commit Message

Lukasz Luba March 22, 2024, 11:08 a.m. UTC 
There is going to be a new update function addressing chip binning.
Therefore, some common code which can be refactored and called from
upcoming changes and em_adjust_new_capacity(). In this way the code
duplication can be avoided.

Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
---
 kernel/power/energy_model.c | 58 +++++++++++++++++++++++++------------
 1 file changed, 39 insertions(+), 19 deletions(-)

Comments

Lukasz Luba March 26, 2024, 8:36 p.m. UTC | #1 
On 3/26/24 10:51, Dietmar Eggemann wrote:
> On 22/03/2024 12:08, Lukasz Luba wrote:
> 
> Maybe better : "PM: EM: Refactoring em_adjust_new_capacity()" ?
> 
>> There is going to be a new update function addressing chip binning.
>> Therefore, some common code which can be refactored and called from
>> upcoming changes and em_adjust_new_capacity(). In this way the code
>> duplication can be avoided.
> 
> IMHO, that's hard to digest.
> 
> Extract em_table_dup() and em_recalc_and_update() from
> em_adjust_new_capacity(). Both functions will be later reused by the
> 'update EM due to chip binning' functionality.

That looks good, I'll update it.

> 
> [...]
> 
>> +static int em_recalc_and_update(struct device *dev, struct em_perf_domain *pd,
>> +				struct em_perf_table __rcu *em_table)
>> +{
>> +	int ret;
>> +
>> +	ret = em_compute_costs(dev, em_table->state, NULL, pd->nr_perf_states,
>>   			       pd->flags);
>> -	if (ret) {
>> -		dev_warn(dev, "EM: compute costs failed\n");
>> -		return;
>> -	}
>> +	if (ret)
>> +		goto free_em_table;
> 
> There seems to be a subtle change in this patch. When em_compute_costs()
> fails now em_table_free() is called. This wasn't the case before when
> em_compute_costs() was directly called from em_adjust_new_capacity().

Yes, I've refactored it to explicitly call to the same free_em_table
for both fails in the new code. It should have been done in old code.

> 
> [...]
diff mbox series

Patch

diff --git a/kernel/power/energy_model.c b/kernel/power/energy_model.c
index 9e1c9aa399ea9..6960dd7393b2d 100644
--- a/kernel/power/energy_model.c
+++ b/kernel/power/energy_model.c
@@ -674,23 +674,15 @@  void em_dev_unregister_perf_domain(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(em_dev_unregister_perf_domain);
 
-/*
- * Adjustment of CPU performance values after boot, when all CPUs capacites
- * are correctly calculated.
- */
-static void em_adjust_new_capacity(struct device *dev,
-				   struct em_perf_domain *pd,
-				   u64 max_cap)
+static struct em_perf_table __rcu *em_table_dup(struct em_perf_domain *pd)
 {
 	struct em_perf_table __rcu *em_table;
 	struct em_perf_state *ps, *new_ps;
-	int ret, ps_size;
+	int ps_size;
 
 	em_table = em_table_alloc(pd);
-	if (!em_table) {
-		dev_warn(dev, "EM: allocation failed\n");
-		return;
-	}
+	if (!em_table)
+		return NULL;
 
 	new_ps = em_table->state;
 
@@ -702,24 +694,52 @@  static void em_adjust_new_capacity(struct device *dev,
 
 	rcu_read_unlock();
 
-	em_init_performance(dev, pd, new_ps, pd->nr_perf_states);
-	ret = em_compute_costs(dev, new_ps, NULL, pd->nr_perf_states,
+	return em_table;
+}
+
+static int em_recalc_and_update(struct device *dev, struct em_perf_domain *pd,
+				struct em_perf_table __rcu *em_table)
+{
+	int ret;
+
+	ret = em_compute_costs(dev, em_table->state, NULL, pd->nr_perf_states,
 			       pd->flags);
-	if (ret) {
-		dev_warn(dev, "EM: compute costs failed\n");
-		return;
-	}
+	if (ret)
+		goto free_em_table;
 
 	ret = em_dev_update_perf_domain(dev, em_table);
 	if (ret)
-		dev_warn(dev, "EM: update failed %d\n", ret);
+		goto free_em_table;
 
 	/*
 	 * This is one-time-update, so give up the ownership in this updater.
 	 * The EM framework has incremented the usage counter and from now
 	 * will keep the reference (then free the memory when needed).
 	 */
+free_em_table:
 	em_table_free(em_table);
+	return ret;
+}
+
+/*
+ * Adjustment of CPU performance values after boot, when all CPUs capacites
+ * are correctly calculated.
+ */
+static void em_adjust_new_capacity(struct device *dev,
+				   struct em_perf_domain *pd,
+				   u64 max_cap)
+{
+	struct em_perf_table __rcu *em_table;
+
+	em_table = em_table_dup(pd);
+	if (!em_table) {
+		dev_warn(dev, "EM: allocation failed\n");
+		return;
+	}
+
+	em_init_performance(dev, pd, em_table->state, pd->nr_perf_states);
+
+	em_recalc_and_update(dev, pd, em_table);
 }
 
 static void em_check_capacity_update(void)