Re: [PATCH 2/2][v3] PM / s2idle: Code cleanup to make s2idle consistent with normal idle path
From: Rafael J. Wysocki <hidden>
Date: 2020-06-23 17:58:03
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On Tuesday, June 23, 2020 8:31:52 AM CEST Chen Yu wrote:
quoted hunk ↗ jump to hunk
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.
quoted hunk ↗ jump to hunk
+ 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 <redacted> 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 <redacted> --- 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 */