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

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Message-ID: <d55f0f78-f2a3-47cb-a070-e35edfad710d@amd.com>
Date: Mon, 24 Mar 2025 09:25:12 -0500
From: Mario Limonciello <mario.limonciello@....com>
To: Kurt Borja <kuurtb@...il.com>, "Rafael J. Wysocki" <rafael@...nel.org>,
 Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
 Mark Pearson <mpearson-lenovo@...ebb.ca>
Cc: Armin Wolf <W_Armin@....de>, Len Brown <lenb@...nel.org>,
 linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] ACPI: platform_profile: Optimize _aggregate_choices()

On 3/22/2025 16:03, Kurt Borja wrote:
> 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.
> 
> Signed-off-by: Kurt Borja <kuurtb@...il.com>

Good find!  This optimization is valid because of the changes in

commit 778b94d7ac17b ("ACPI: platform_profile: Add support for hidden 
choices")

Reviewed-by: Mario Limonciello <mario.limonciello@....com>

> ---
>   drivers/acpi/platform_profile.c | 10 +++-------
>   1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/acpi/platform_profile.c b/drivers/acpi/platform_profile.c
> index ef9444482db1982b19d2a17884e1c3ab0e5cb55c..b5b24b075af6dfa612d56eb95342c6af87a60d3e 100644
> --- a/drivers/acpi/platform_profile.c
> +++ b/drivers/acpi/platform_profile.c
> @@ -256,12 +256,10 @@ 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 +303,6 @@ 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 +419,7 @@ 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 +499,6 @@ 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,