Re: [PATCH] powerpc/time: enable sched clock for irqtime

[Michael Ellerman]

On Thu, 22 Oct 2020 14:51:19 +0800, Pingfan Liu wrote:
> When CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING_GEN, powerpc
> does not enable "sched_clock_irqtime" and can not utilize irq time
> accounting.
> 
> Like x86, powerpc does not use the sched_clock_register() interface. So it
> needs an dedicated call to enable_sched_clock_irqtime() to enable irq time
> accounting.

Applied to powerpc/next.

[1/1] powerpc/time: Enable sched clock for irqtime
  https://git.kernel.org/powerpc/c/b709e32ef570b8b91dfbcb63cffac4324c87799f

cheers

Re: [PATCH] powerpc/time: enable sched clock for irqtime

[Pingfan Liu]

I encounter a irq flood on Power9 machine, and tries a way to work
around it by https://www.spinics.net/lists/kernel/msg3705028.html

As irq time accounting is the foundation for the method, it needs to
make irq accounting take effect on powerpc platform.

On Thu, Oct 22, 2020 at 2:51 PM Pingfan Liu  wrote:
>
> When CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING_GEN, powerpc
> does not enable "sched_clock_irqtime" and can not utilize irq time
> accounting.
>
> Like x86, powerpc does not use the sched_clock_register() interface. So it
> needs an dedicated call to enable_sched_clock_irqtime() to enable irq time
> accounting.
>
> Signed-off-by: Pingfan Liu 
> Cc: Michael Ellerman 
> Cc: Christophe Leroy 
> Cc: Nicholas Piggin 
> To: linuxppc-dev@lists.ozlabs.org
> ---
>  arch/powerpc/kernel/time.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
> index f85539e..4083b59e 100644
> --- a/arch/powerpc/kernel/time.c
> +++ b/arch/powerpc/kernel/time.c
> @@ -53,6 +53,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  #include 
>  #include 
>
> @@ -1134,6 +1135,7 @@ void __init time_init(void)
> tick_setup_hrtimer_broadcast();
>
> of_clk_init(NULL);
> +   enable_sched_clock_irqtime();
>  }
>
>  /*
> --
> 2.7.5
>

[PATCH] powerpc/time: enable sched clock for irqtime

[Pingfan Liu]

When CONFIG_IRQ_TIME_ACCOUNTING and CONFIG_VIRT_CPU_ACCOUNTING_GEN, powerpc
does not enable "sched_clock_irqtime" and can not utilize irq time
accounting.

Like x86, powerpc does not use the sched_clock_register() interface. So it
needs an dedicated call to enable_sched_clock_irqtime() to enable irq time
accounting.

Signed-off-by: Pingfan Liu 
Cc: Michael Ellerman 
Cc: Christophe Leroy 
Cc: Nicholas Piggin 
To: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/time.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index f85539e..4083b59e 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -53,6 +53,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 
@@ -1134,6 +1135,7 @@ void __init time_init(void)
tick_setup_hrtimer_broadcast();
 
of_clk_init(NULL);
+   enable_sched_clock_irqtime();
 }
 
 /*
-- 
2.7.5