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

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Message-ID: <CAJZ5v0iFMM5G48OfkZjnqkBK5rOLxKh=C-O5r3=WsWpTF8aXtA@mail.gmail.com>
Date: Thu, 27 Mar 2025 20:46:38 +0100
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Kurt Borja <kuurtb@...il.com>
Cc: "Rafael J. Wysocki" <rafael@...nel.org>, Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>, 
	Mark Pearson <mpearson-lenovo@...ebb.ca>, 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
Subject: Re: [PATCH v2] ACPI: platform_profile: Optimize _aggregate_choices()

On Tue, Mar 25, 2025 at 9:40 PM Kurt Borja <kuurtb@...il.com> 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.
>
> 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);
>
> ---

Applied as 6.15-rc material, thanks!