linux-kernel - [PATCH v2] ACPI: platform_profile: Optimize _aggregate

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Message-Id: <20250325-pprof-opt-v2-1-736291e6e66b@gmail.com>
Date: Tue, 25 Mar 2025 17:39:53 -0300
From: Kurt Borja <kuurtb@...il.com>
To: "Rafael J. Wysocki" <rafael@...nel.org>, 
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, 
 Mark Pearson <mpearson-lenovo@...ebb.ca>
Cc: Mario Limonciello <mario.limonciello@....com>, 
 Armin Wolf <W_Armin@....de>, Len Brown <lenb@...nel.org>, 
 linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org, 
 Kurt Borja <kuurtb@...il.com>
Subject: [PATCH v2] ACPI: platform_profile: Optimize _aggregate_choices()

Choices aggregates passed to _aggregate_choices() are already filled
with ones, therefore we can avoid copying a new bitmap on the first
iteration.

This makes setting the PLATFORM_PROFILE_LAST bit on aggregates
unnecessary, so drop it as well.

While at it, add a couple empty lines to improve style.

Reviewed-by: Armin Wolf <W_Armin@....de>
Reviewed-by: Mario Limonciello <mario.limonciello@....com>
Signed-off-by: Kurt Borja <kuurtb@...il.com>
---
Changes in v2:
- Mention bitmap requirements in kernel-doc
- Link to v1: https://lore.kernel.org/r/20250322-pprof-opt-v1-1-105455879a82@gmail.com
---
 drivers/acpi/platform_profile.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
index ef9444482db1982b19d2a17884e1c3ab0e5cb55c..26d7ba49e9dcff1fded246cb6b5c836b180e07e8 100644
--- a/drivers/acpi/platform_profile.c
+++ b/drivers/acpi/platform_profile.c
@@ -245,7 +245,8 @@ static const struct class platform_profile_class = {
 /**
  * _aggregate_choices - Aggregate the available profile choices
  * @dev: The device
- * @arg: struct aggregate_choices_data
+ * @arg: struct aggregate_choices_data, with it's aggregate member bitmap
+ *	 initially filled with ones
  *
  * Return: 0 on success, -errno on failure
  */
@@ -256,12 +257,10 @@ static int _aggregate_choices(struct device *dev, void *arg)
 	struct platform_profile_handler *handler;
 
 	lockdep_assert_held(&profile_lock);
+
 	handler = to_pprof_handler(dev);
 	bitmap_or(tmp, handler->choices, handler->hidden_choices, PLATFORM_PROFILE_LAST);
-	if (test_bit(PLATFORM_PROFILE_LAST, data->aggregate))
-		bitmap_copy(data->aggregate, tmp, PLATFORM_PROFILE_LAST);
-	else
-		bitmap_and(data->aggregate, tmp, data->aggregate, PLATFORM_PROFILE_LAST);
+	bitmap_and(data->aggregate, tmp, data->aggregate, PLATFORM_PROFILE_LAST);
 	data->count++;
 
 	return 0;
@@ -305,7 +304,6 @@ static ssize_t platform_profile_choices_show(struct device *dev,
 	};
 	int err;
 
-	set_bit(PLATFORM_PROFILE_LAST, data.aggregate);
 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
 		err = class_for_each_device(&platform_profile_class, NULL,
 					    &data, _aggregate_choices);
@@ -422,7 +420,7 @@ static ssize_t platform_profile_store(struct device *dev,
 	i = sysfs_match_string(profile_names, buf);
 	if (i < 0 || i == PLATFORM_PROFILE_CUSTOM)
 		return -EINVAL;
-	set_bit(PLATFORM_PROFILE_LAST, data.aggregate);
+
 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
 		ret = class_for_each_device(&platform_profile_class, NULL,
 					    &data, _aggregate_choices);
@@ -502,7 +500,6 @@ int platform_profile_cycle(void)
 	enum platform_profile_option profile = PLATFORM_PROFILE_LAST;
 	int err;
 
-	set_bit(PLATFORM_PROFILE_LAST, data.aggregate);
 	scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &profile_lock) {
 		err = class_for_each_device(&platform_profile_class, NULL,
 					    &profile, _aggregate_profiles);

---
base-commit: 9a43102daf64dd0d172d8b39836dbc1dba4da1ea
change-id: 20250322-pprof-opt-caa7f7f349b8

Best regards,
-- 
 ~ Kurt