x86: add power_end event to process_*.c cpu_idle routine
PATCH 1/1 x86: add power_end event to process_*.c cpu_idle routine
From: Robert Schöne <[email protected]>
Systems using the idle thread from process_32.c and process_64.c do not generate power_end events which could be traced using perf. This patch adds the event generation for such systems.
Signed-off-by Robert Schöne <[email protected]>
Acked-by Arjan van de Ven <[email protected]>
---
The smp_processor_id() is given to power_end as i hope that the changed interface defined in http://lkml.org/lkml/2010/4/27/271 will be part of the standard tree one day. (It is currently part of the -mm tree.) As long as this new interface is not included in the standard tree, this patch won't make no harm. When it will be included, this code does not have to be touched anymore.
arch/x86/kernel/process_32.c | 4 ++++ arch/x86/kernel/process_64.c | 5 +++++ 2 files changed, 9 insertions(+), 0 deletions(-)
arch/x86/kernel/process_32.c +4 -0
@@ -58,6 +58,8 @@#include <asm/ds.h> #include <asm/debugreg.h> +#include <trace/events/power.h> + asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");/*
@@ -112,6 +114,8 @@ void cpu_idle(void)stop_critical_timings ();pm_idle ();start_critical_timings (); + +trace_power_end (smp_processor_id ()); }tick_nohz_restart_sched_tick ();preempt_enable_no_resched ();
arch/x86/kernel/process_64.c +5 -0
@@ -52,6 +52,8 @@#include <asm/ds.h> #include <asm/debugreg.h> +#include <trace/events/power.h> + asmlinkage extern void ret_from_fork(void); DEFINE_PER_CPU(unsigned long, old_rsp);
@@ -139,6 +141,9 @@ void cpu_idle(void)stop_critical_timings ();pm_idle ();start_critical_timings (); + +trace_power_end (smp_processor_id ()); +/* In many cases the interrupt that ended idle has already called exit_idle. But some idle loops can be woken up without interrupt. */