Re: [PATCH 1/2] ftrace: add notrace to ARM sched_clock routines

From: Steven Rostedt
Date: Fri May 01 2009 - 19:04:21 EST



On Fri, 1 May 2009, Tim Bird wrote:

> Add notrace attribute to sched_clock, to avoid
> recursion with ftrace function_graph tracing.

If there's nothing in those files that you don't really want to trace
anyway, you could just disable the tracing from those files:

For example, in the Makefile add:

CFLAGS_REMOVE_time.o := -pg

-- Steve

>
> Signed-off-by: Tim Bird <tim.bird@xxxxxxxxxxx>
> ---
> arch/arm/mach-mmp/time.c | 2 +-
> arch/arm/mach-pxa/time.c | 2 +-
> arch/arm/mach-realview/core.c | 2 +-
> arch/arm/mach-sa1100/generic.c | 2 +-
> arch/arm/mach-versatile/core.c | 2 +-
> arch/arm/plat-omap/common.c | 4 ++--
> 6 files changed, 7 insertions(+), 7 deletions(-)
>
> --- a/arch/arm/mach-mmp/time.c
> +++ b/arch/arm/mach-mmp/time.c
> @@ -72,7 +72,7 @@ static inline uint32_t timer_read(void)
> return __raw_readl(TIMERS_VIRT_BASE + TMR_CVWR(0));
> }
>
> -unsigned long long sched_clock(void)
> +unsigned long long notrace sched_clock(void)
> {
> unsigned long long v = cnt32_to_63(timer_read());
> return (v * tcr2ns_scale) >> TCR2NS_SCALE_FACTOR;
> --- a/arch/arm/mach-pxa/time.c
> +++ b/arch/arm/mach-pxa/time.c
> @@ -51,7 +51,7 @@ static void __init set_oscr2ns_scale(uns
> oscr2ns_scale++;
> }
>
> -unsigned long long sched_clock(void)
> +unsigned long long notrace sched_clock(void)
> {
> unsigned long long v = cnt32_to_63(OSCR);
> return (v * oscr2ns_scale) >> OSCR2NS_SCALE_FACTOR;
> --- a/arch/arm/mach-realview/core.c
> +++ b/arch/arm/mach-realview/core.c
> @@ -60,7 +60,7 @@ void __iomem *gic_cpu_base_addr;
> * This is the RealView sched_clock implementation. This has
> * a resolution of 41.7ns, and a maximum value of about 179s.
> */
> -unsigned long long sched_clock(void)
> +unsigned long long notrace sched_clock(void)
> {
> unsigned long long v;
>
> --- a/arch/arm/mach-sa1100/generic.c
> +++ b/arch/arm/mach-sa1100/generic.c
> @@ -131,7 +131,7 @@ EXPORT_SYMBOL(cpufreq_get);
> *
> * ( * 1E9 / 3686400 => * 78125 / 288)
> */
> -unsigned long long sched_clock(void)
> +unsigned long long notrace sched_clock(void)
> {
> unsigned long long v = cnt32_to_63(OSCR);
>
> --- a/arch/arm/mach-versatile/core.c
> +++ b/arch/arm/mach-versatile/core.c
> @@ -237,7 +237,7 @@ void __init versatile_map_io(void)
> * long as there is always less than 89 seconds between successive
> * calls to this function.
> */
> -unsigned long long sched_clock(void)
> +unsigned long long notrace sched_clock(void)
> {
> unsigned long long v = cnt32_to_63(readl(VERSATILE_REFCOUNTER));
>
> --- a/arch/arm/plat-omap/common.c
> +++ b/arch/arm/plat-omap/common.c
> @@ -185,7 +185,7 @@ console_initcall(omap_add_serial_console
>
> #include <linux/clocksource.h>
>
> -static cycle_t omap_32k_read(struct clocksource *cs)
> +static cycle_t notrace omap_32k_read(struct clocksource *cs)
> {
> return omap_readl(TIMER_32K_SYNCHRONIZED);
> }
> @@ -203,7 +203,7 @@ static struct clocksource clocksource_32
> * Returns current time from boot in nsecs. It's OK for this to wrap
> * around for now, as it's just a relative time stamp.
> */
> -unsigned long long sched_clock(void)
> +unsigned long long notrace sched_clock(void)
> {
> unsigned long long ret;
>
>
>
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