From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Chen Yu <yu.c.chen@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Len Brown <len.brown@intel.com>,
linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
Len Brown <lenb@kernel.org>
Subject: Re: [PATCH 2/2][v3] PM / s2idle: Code cleanup to make s2idle consistent with normal idle path
Date: Tue, 23 Jun 2020 19:57:59 +0200 [thread overview]
Message-ID: <15473183.xuek0xzqYe@kreacher> (raw)
In-Reply-To: <a00278cc5db9f4845006cff130fd91a58c0d92d1.1592892767.git.yu.c.chen@intel.com>
On Tuesday, June 23, 2020 8:31:52 AM CEST Chen Yu wrote:
> Currently s2idle is a little different from the normal idle path. This
> patch makes call_s2idle() consistent with call_cpuidle(), and also
> s2idle_enter() is analogous to cpuidle_enter().
>
> No functional change.
>
> Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Len Brown <lenb@kernel.org>
> Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
> Signed-off-by: Chen Yu <yu.c.chen@intel.com>
> ---
> drivers/cpuidle/cpuidle.c | 17 +++++++++++++----
> 1 file changed, 13 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index e092789187c6..b2e764d1ac99 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -134,8 +134,8 @@ int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
> }
>
> #ifdef CONFIG_SUSPEND
> -static void enter_s2idle_proper(struct cpuidle_driver *drv,
> - struct cpuidle_device *dev, int index)
> +static void s2idle_enter(struct cpuidle_driver *drv,
> + struct cpuidle_device *dev, int index)
> {
> ktime_t time_start, time_end;
>
> @@ -169,6 +169,15 @@ static void enter_s2idle_proper(struct cpuidle_driver *drv,
> dev->states_usage[index].s2idle_usage++;
> }
>
> +static int call_s2idle(struct cpuidle_driver *drv,
> + struct cpuidle_device *dev, int index)
> +{
> + if (!current_clr_polling_and_test())
> + s2idle_enter(drv, dev, index);
> +
Well, I'd rather move the definition of this function to idle.c, because it is
better to call current_clr_polling_and_test() from there.
> + return index;
> +}
> +
> /**
> * cpuidle_enter_s2idle - Enter an idle state suitable for suspend-to-idle.
> * @drv: cpuidle driver for the given CPU.
> @@ -187,8 +196,8 @@ int cpuidle_enter_s2idle(struct cpuidle_driver *drv, struct cpuidle_device *dev)
> * be frozen safely.
> */
> index = find_deepest_state(drv, dev, U64_MAX, 0, true);
> - if (index > 0 && !current_clr_polling_and_test())
> - enter_s2idle_proper(drv, dev, index);
> + if (index > 0)
> + call_s2idle(drv, dev, index);
This can be made look more like cpuidle_enter() too.
>
> return index;
> }
>
So overall I'd prefer to apply something like this (on top of the [1/2]):
---
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Subject: [PATCH] cpuidle: Rearrange s2idle-specific idle state entry code
Implement call_cpuidle_s2idle() in analogy with call_cpuidle()
for the s2idle-specific idle state entry and invoke it from
cpuidle_idle_call() to make the s2idle-specific idle entry code
path look more similar to the "regular" idle entry one.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/cpuidle/cpuidle.c | 6 +++---
kernel/sched/idle.c | 15 +++++++++++----
2 files changed, 14 insertions(+), 7 deletions(-)
Index: linux-pm/kernel/sched/idle.c
===================================================================
--- linux-pm.orig/kernel/sched/idle.c
+++ linux-pm/kernel/sched/idle.c
@@ -96,6 +96,15 @@ void __cpuidle default_idle_call(void)
}
}
+static int call_cpuidle_s2idle(struct cpuidle_driver *drv,
+ struct cpuidle_device *dev)
+{
+ if (current_clr_polling_and_test())
+ return -EBUSY;
+
+ return cpuidle_enter_s2idle(drv, dev);
+}
+
static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev,
int next_state)
{
@@ -171,11 +180,9 @@ static void cpuidle_idle_call(void)
if (idle_should_enter_s2idle()) {
rcu_idle_enter();
- entered_state = cpuidle_enter_s2idle(drv, dev);
- if (entered_state > 0) {
- local_irq_enable();
+ entered_state = call_cpuidle_s2idle(drv, dev);
+ if (entered_state > 0)
goto exit_idle;
- }
rcu_idle_exit();
Index: linux-pm/drivers/cpuidle/cpuidle.c
===================================================================
--- linux-pm.orig/drivers/cpuidle/cpuidle.c
+++ linux-pm/drivers/cpuidle/cpuidle.c
@@ -13,7 +13,6 @@
#include <linux/mutex.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
-#include <linux/sched/idle.h>
#include <linux/notifier.h>
#include <linux/pm_qos.h>
#include <linux/cpu.h>
@@ -187,9 +186,10 @@ int cpuidle_enter_s2idle(struct cpuidle_
* be frozen safely.
*/
index = find_deepest_state(drv, dev, U64_MAX, 0, true);
- if (index > 0 && !current_clr_polling_and_test())
+ if (index > 0) {
enter_s2idle_proper(drv, dev, index);
-
+ local_irq_enable();
+ }
return index;
}
#endif /* CONFIG_SUSPEND */
next prev parent reply other threads:[~2020-06-23 17:58 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-23 6:31 [PATCH 0/2][v3] Fix IPI missing issue when woken from suspend to idle Chen Yu
2020-06-23 6:31 ` [PATCH 1/2][v3] PM / s2idle: Clear _TIF_POLLING_NRFLAG before " Chen Yu
2020-06-23 15:13 ` Rafael J. Wysocki
2020-06-23 6:31 ` [PATCH 2/2][v3] PM / s2idle: Code cleanup to make s2idle consistent with normal idle path Chen Yu
2020-06-23 17:57 ` Rafael J. Wysocki [this message]
2020-06-25 5:15 ` Chen Yu
2020-06-25 10:49 ` Rafael J. Wysocki
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