[04/10] cpuidle, psci: Push RCU-idle into driver
Commit Message
From: Peter Zijlstra <peterz@infradead.org>
commit e038f7b8028a1d1bc8ac82351c71ea538f19a879 upstream.
Doing RCU-idle outside the driver, only to then temporarily enable it
again, at least twice, before going idle is suboptimal.
Notably once implicitly through the cpu_pm_*() calls and once
explicitly doing ct_irq_*_irqon().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Kajetan Puchalski <kajetan.puchalski@arm.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20230112195539.760296658@infradead.org
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
---
drivers/cpuidle/cpuidle-psci.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
Comments
Hi Cheng,
On Fri, Mar 3, 2023 at 10:35 AM Cheng-Jui Wang
<cheng-jui.wang@mediatek.com> wrote:
> From: Peter Zijlstra <peterz@infradead.org>
>
> commit e038f7b8028a1d1bc8ac82351c71ea538f19a879 upstream.
>
> Doing RCU-idle outside the driver, only to then temporarily enable it
> again, at least twice, before going idle is suboptimal.
>
> Notably once implicitly through the cpu_pm_*() calls and once
> explicitly doing ct_irq_*_irqon().
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Signed-off-by: Ingo Molnar <mingo@kernel.org>
> Tested-by: Kajetan Puchalski <kajetan.puchalski@arm.com>
> Tested-by: Tony Lindgren <tony@atomide.com>
> Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
> Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
> Reviewed-by: Guo Ren <guoren@kernel.org>
> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> Link: https://lore.kernel.org/r/20230112195539.760296658@infradead.org
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> Signed-off-by: Cheng-Jui Wang <cheng-jui.wang@mediatek.com>
Given this patch introduced a so far unresolved regression upstream,
I think it's premature to backport this to stable.
https://lore.kernel.org/all/ff338b9f-4ab0-741b-26ea-7b7351da156@linux-m68k.org
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
@@ -69,12 +69,12 @@ static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
return -1;
/* Do runtime PM to manage a hierarchical CPU toplogy. */
- ct_irq_enter_irqson();
if (s2idle)
dev_pm_genpd_suspend(pd_dev);
else
pm_runtime_put_sync_suspend(pd_dev);
- ct_irq_exit_irqson();
+
+ ct_idle_enter();
state = psci_get_domain_state();
if (!state)
@@ -82,13 +82,12 @@ static int __psci_enter_domain_idle_state(struct cpuidle_device *dev,
ret = psci_cpu_suspend_enter(state) ? -1 : idx;
- ct_irq_enter_irqson();
+ ct_idle_exit();
+
if (s2idle)
dev_pm_genpd_resume(pd_dev);
else
pm_runtime_get_sync(pd_dev);
- ct_irq_exit_irqson();
-
cpu_pm_exit();
/* Clear the domain state to start fresh when back from idle. */
@@ -240,6 +239,7 @@ static int psci_dt_cpu_init_topology(struct cpuidle_driver *drv,
* of a shared state for the domain, assumes the domain states are all
* deeper states.
*/
+ drv->states[state_count - 1].flags |= CPUIDLE_FLAG_RCU_IDLE;
drv->states[state_count - 1].enter = psci_enter_domain_idle_state;
drv->states[state_count - 1].enter_s2idle = psci_enter_s2idle_domain_idle_state;
psci_cpuidle_use_cpuhp = true;