Hi All,
Currently, cpuidle is paused before the last phase of suspending device
(suspend_noirq), but first it doesn't make sense to pause it for
suspend-to-idle, because suspend-to-idle resumes it anyway later, and
then it need not be paused while suspending devices anyway.
Patch [1/2] removes the pausing and resuming of cpuidle from the suspend-to-idle
path and patch [1/2] combines these operations with the disabling and enabling
of secondary CPUs (which does not take place in the suspend-to-idle path),
respectively.
Thanks!
From: Rafael J. Wysocki <[email protected]>
It is pointless to pause cpuidle in the suspend-to-idle path,
because it is going to be resumed in the same path later and
pausing it does not serve any particular purpose in that case.
Rework the code to avoid doing that.
Signed-off-by: Rafael J. Wysocki <[email protected]>
---
drivers/base/power/main.c | 11 ++++++-----
kernel/power/suspend.c | 8 ++++++--
2 files changed, 12 insertions(+), 7 deletions(-)
Index: linux-pm/drivers/base/power/main.c
===================================================================
--- linux-pm.orig/drivers/base/power/main.c
+++ linux-pm/drivers/base/power/main.c
@@ -747,8 +747,6 @@ void dpm_resume_noirq(pm_message_t state
resume_device_irqs();
device_wakeup_disarm_wake_irqs();
-
- cpuidle_resume();
}
/**
@@ -881,6 +879,7 @@ void dpm_resume_early(pm_message_t state
void dpm_resume_start(pm_message_t state)
{
dpm_resume_noirq(state);
+ cpuidle_resume();
dpm_resume_early(state);
}
EXPORT_SYMBOL_GPL(dpm_resume_start);
@@ -1336,8 +1335,6 @@ int dpm_suspend_noirq(pm_message_t state
{
int ret;
- cpuidle_pause();
-
device_wakeup_arm_wake_irqs();
suspend_device_irqs();
@@ -1521,9 +1518,13 @@ int dpm_suspend_end(pm_message_t state)
if (error)
goto out;
+ cpuidle_pause();
+
error = dpm_suspend_noirq(state);
- if (error)
+ if (error) {
+ cpuidle_resume();
dpm_resume_early(resume_event(state));
+ }
out:
dpm_show_time(starttime, state, error, "end");
Index: linux-pm/kernel/power/suspend.c
===================================================================
--- linux-pm.orig/kernel/power/suspend.c
+++ linux-pm/kernel/power/suspend.c
@@ -97,7 +97,6 @@ static void s2idle_enter(void)
raw_spin_unlock_irq(&s2idle_lock);
cpus_read_lock();
- cpuidle_resume();
/* Push all the CPUs into the idle loop. */
wake_up_all_idle_cpus();
@@ -105,7 +104,6 @@ static void s2idle_enter(void)
swait_event_exclusive(s2idle_wait_head,
s2idle_state == S2IDLE_STATE_WAKE);
- cpuidle_pause();
cpus_read_unlock();
raw_spin_lock_irq(&s2idle_lock);
@@ -405,6 +403,9 @@ static int suspend_enter(suspend_state_t
if (error)
goto Devices_early_resume;
+ if (state != PM_SUSPEND_TO_IDLE)
+ cpuidle_pause();
+
error = dpm_suspend_noirq(PMSG_SUSPEND);
if (error) {
pr_err("noirq suspend of devices failed\n");
@@ -459,6 +460,9 @@ static int suspend_enter(suspend_state_t
dpm_resume_noirq(PMSG_RESUME);
Platform_early_resume:
+ if (state != PM_SUSPEND_TO_IDLE)
+ cpuidle_resume();
+
platform_resume_early(state);
Devices_early_resume:
On Fri, 22 Oct 2021 at 18:08, Rafael J. Wysocki <[email protected]> wrote:
>
> From: Rafael J. Wysocki <[email protected]>
>
> It is pointless to pause cpuidle in the suspend-to-idle path,
> because it is going to be resumed in the same path later and
> pausing it does not serve any particular purpose in that case.
>
> Rework the code to avoid doing that.
>
> Signed-off-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>
Tested-by: Ulf Hansson <[email protected]>
Kind regards
Uffe
> ---
> drivers/base/power/main.c | 11 ++++++-----
> kernel/power/suspend.c | 8 ++++++--
> 2 files changed, 12 insertions(+), 7 deletions(-)
>
> Index: linux-pm/drivers/base/power/main.c
> ===================================================================
> --- linux-pm.orig/drivers/base/power/main.c
> +++ linux-pm/drivers/base/power/main.c
> @@ -747,8 +747,6 @@ void dpm_resume_noirq(pm_message_t state
>
> resume_device_irqs();
> device_wakeup_disarm_wake_irqs();
> -
> - cpuidle_resume();
> }
>
> /**
> @@ -881,6 +879,7 @@ void dpm_resume_early(pm_message_t state
> void dpm_resume_start(pm_message_t state)
> {
> dpm_resume_noirq(state);
> + cpuidle_resume();
> dpm_resume_early(state);
> }
> EXPORT_SYMBOL_GPL(dpm_resume_start);
> @@ -1336,8 +1335,6 @@ int dpm_suspend_noirq(pm_message_t state
> {
> int ret;
>
> - cpuidle_pause();
> -
> device_wakeup_arm_wake_irqs();
> suspend_device_irqs();
>
> @@ -1521,9 +1518,13 @@ int dpm_suspend_end(pm_message_t state)
> if (error)
> goto out;
>
> + cpuidle_pause();
> +
> error = dpm_suspend_noirq(state);
> - if (error)
> + if (error) {
> + cpuidle_resume();
> dpm_resume_early(resume_event(state));
> + }
>
> out:
> dpm_show_time(starttime, state, error, "end");
> Index: linux-pm/kernel/power/suspend.c
> ===================================================================
> --- linux-pm.orig/kernel/power/suspend.c
> +++ linux-pm/kernel/power/suspend.c
> @@ -97,7 +97,6 @@ static void s2idle_enter(void)
> raw_spin_unlock_irq(&s2idle_lock);
>
> cpus_read_lock();
> - cpuidle_resume();
>
> /* Push all the CPUs into the idle loop. */
> wake_up_all_idle_cpus();
> @@ -105,7 +104,6 @@ static void s2idle_enter(void)
> swait_event_exclusive(s2idle_wait_head,
> s2idle_state == S2IDLE_STATE_WAKE);
>
> - cpuidle_pause();
> cpus_read_unlock();
>
> raw_spin_lock_irq(&s2idle_lock);
> @@ -405,6 +403,9 @@ static int suspend_enter(suspend_state_t
> if (error)
> goto Devices_early_resume;
>
> + if (state != PM_SUSPEND_TO_IDLE)
> + cpuidle_pause();
> +
> error = dpm_suspend_noirq(PMSG_SUSPEND);
> if (error) {
> pr_err("noirq suspend of devices failed\n");
> @@ -459,6 +460,9 @@ static int suspend_enter(suspend_state_t
> dpm_resume_noirq(PMSG_RESUME);
>
> Platform_early_resume:
> + if (state != PM_SUSPEND_TO_IDLE)
> + cpuidle_resume();
> +
> platform_resume_early(state);
>
> Devices_early_resume:
>
>
>
>
>
>
>