pm/sleep: Add PM_USERSPACE_AUTOSLEEP Kconfig

Systems that initiate frequent suspend/resume from userspace
can make the kernel aware by enabling PM_USERSPACE_AUTOSLEEP
config.

This allows for certain sleep-sensitive code (wireguard/rng) to
decide on what preparatory work should be performed (or not) in
their pm_notification callbacks.

This patch was prompted by the discussion at [1] which attempts
to remove CONFIG_ANDROID that currently guards these code paths.

[1] https://lore.kernel.org/r/20220629150102.1582425-1-hch@lst.de/

Suggested-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Link: https://lore.kernel.org/r/20220630191230.235306-1-kaleshsingh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kalesh Singh 2022-06-30 19:12:29 +00:00 committed by Greg Kroah-Hartman
parent 80fc671bcc
commit 261e224d6a
3 changed files with 24 additions and 3 deletions

View File

@ -755,8 +755,8 @@ static int random_pm_notification(struct notifier_block *nb, unsigned long actio
spin_unlock_irqrestore(&input_pool.lock, flags);
if (crng_ready() && (action == PM_RESTORE_PREPARE ||
(action == PM_POST_SUSPEND &&
!IS_ENABLED(CONFIG_PM_AUTOSLEEP) && !IS_ENABLED(CONFIG_ANDROID)))) {
(action == PM_POST_SUSPEND && !IS_ENABLED(CONFIG_PM_AUTOSLEEP) &&
!IS_ENABLED(CONFIG_PM_USERSPACE_AUTOSLEEP)))) {
crng_reseed();
pr_notice("crng reseeded on system resumption\n");
}

View File

@ -69,7 +69,8 @@ static int wg_pm_notification(struct notifier_block *nb, unsigned long action, v
* its normal operation rather than as a somewhat rare event, then we
* don't actually want to clear keys.
*/
if (IS_ENABLED(CONFIG_PM_AUTOSLEEP) || IS_ENABLED(CONFIG_ANDROID))
if (IS_ENABLED(CONFIG_PM_AUTOSLEEP) ||
IS_ENABLED(CONFIG_PM_USERSPACE_AUTOSLEEP))
return 0;
if (action != PM_HIBERNATION_PREPARE && action != PM_SUSPEND_PREPARE)

View File

@ -143,6 +143,26 @@ config PM_AUTOSLEEP
Allow the kernel to trigger a system transition into a global sleep
state automatically whenever there are no active wakeup sources.
config PM_USERSPACE_AUTOSLEEP
bool "Userspace opportunistic sleep"
depends on PM_SLEEP
help
Notify kernel of aggressive userspace autosleep power management policy.
This option changes the behavior of various sleep-sensitive code to deal
with frequent userspace-initiated transitions into a global sleep state.
Saying Y here, disables code paths that most users really should keep
enabled. In particular, only enable this if it is very common to be
asleep/awake for very short periods of time (<= 2 seconds).
Only platforms, such as Android, that implement opportunistic sleep from
a userspace power manager service should enable this option; and not
other machines. Therefore, you should say N here, unless you are
extremely certain that this is what you want. The option otherwise has
bad, undesirable effects, and should not be enabled just for fun.
config PM_WAKELOCKS
bool "User space wakeup sources interface"
depends on PM_SLEEP