2006-08-04 03:26:14

by Daniel Walker

Subject: [PATCH 07/10] -mm clocksource: remove update_callback

With the new notifier block the update_callback becomes
obsolete.

Signed-Off-By: Daniel Walker <[email protected]>
---
arch/i386/kernel/tsc.c | 5 +++--
include/linux/clocksource.h | 2 --
2 files changed, 3 insertions(+), 4 deletions(-)

Index: linux-2.6.17/arch/i386/kernel/tsc.c
===================================================================
--- linux-2.6.17.orig/arch/i386/kernel/tsc.c
+++ linux-2.6.17/arch/i386/kernel/tsc.c
@@ -60,9 +60,12 @@ static inline int check_tsc_unstable(voi
return tsc_unstable;
}

+static int tsc_update_callback(void);
void mark_tsc_unstable(void)
{
tsc_unstable = 1;
+
+ tsc_update_callback();
}
EXPORT_SYMBOL_GPL(mark_tsc_unstable);

@@ -322,7 +325,6 @@ core_initcall(cpufreq_tsc);
/* clock source code */

static unsigned long current_tsc_khz = 0;
-static int tsc_update_callback(void);

static cycle_t read_tsc(void)
{
@@ -340,7 +342,6 @@ static struct clocksource clocksource_ts
.mask = CLOCKSOURCE_MASK(64),
.mult = 0, /* to be set */
.shift = 22,
- .update_callback = tsc_update_callback,
.is_continuous = 1,
};

Index: linux-2.6.17/include/linux/clocksource.h
===================================================================
--- linux-2.6.17.orig/include/linux/clocksource.h
+++ linux-2.6.17/include/linux/clocksource.h
@@ -60,7 +60,6 @@ extern struct clocksource clocksource_ji
* subtraction of non 64 bit counters
* @mult: cycle to nanosecond multiplier
* @shift: cycle to nanosecond divisor (power of two)
- * @update_callback: called when safe to alter clocksource values
* @is_continuous: defines if clocksource is free-running.
* @cycle_interval: Used internally by timekeeping core, please ignore.
* @xtime_interval: Used internally by timekeeping core, please ignore.
@@ -73,7 +72,6 @@ struct clocksource {
cycle_t mask;
u32 mult;
u32 shift;
- int (*update_callback)(void);
int is_continuous;

/* timekeeping specific data, ignore */

--

2006-08-04 19:28:05

by john stultz

Subject: Re: [PATCH 07/10] -mm clocksource: remove update_callback

On Thu, 2006-08-03 at 20:24 -0700, [email protected] wrote:
> plain text document attachment
> (clocksource_remove_update_callback.patch)
> With the new notifier block the update_callback becomes
> obsolete.
>
> Signed-Off-By: Daniel Walker <[email protected]>
> ---
> arch/i386/kernel/tsc.c | 5 +++--
> include/linux/clocksource.h | 2 --
> 2 files changed, 3 insertions(+), 4 deletions(-)
>
> Index: linux-2.6.17/arch/i386/kernel/tsc.c
> ===================================================================
> --- linux-2.6.17.orig/arch/i386/kernel/tsc.c
> +++ linux-2.6.17/arch/i386/kernel/tsc.c
> @@ -60,9 +60,12 @@ static inline int check_tsc_unstable(voi
> return tsc_unstable;
> }
>
> +static int tsc_update_callback(void);
> void mark_tsc_unstable(void)
> {
> tsc_unstable = 1;
> +
> + tsc_update_callback();
> }
> EXPORT_SYMBOL_GPL(mark_tsc_unstable);

Hmm. I'd like to keep mark_tsc_unstable to just be a flag rather then
the hook into the update_callback(), as it may be called quite
frequently.

I do agree we can kill the update_callback all together, but we probably
need to do sometihng like:

void mark_tsc_unstable(void)
{
if (unlikely(!tsc_unstable)) {
clocksource_tsc.rating = 50;
clocksource_rating_change(&clocksource_tsc);
}
tsc_unstable = 1;
}


> @@ -322,7 +325,6 @@ core_initcall(cpufreq_tsc);
> /* clock source code */
>
> static unsigned long current_tsc_khz = 0;
> -static int tsc_update_callback(void);
>
> static cycle_t read_tsc(void)
> {
> @@ -340,7 +342,6 @@ static struct clocksource clocksource_ts
> .mask = CLOCKSOURCE_MASK(64),
> .mult = 0, /* to be set */
> .shift = 22,
> - .update_callback = tsc_update_callback,
> .is_continuous = 1,
> };
>
> Index: linux-2.6.17/include/linux/clocksource.h
> ===================================================================
> --- linux-2.6.17.orig/include/linux/clocksource.h
> +++ linux-2.6.17/include/linux/clocksource.h
> @@ -60,7 +60,6 @@ extern struct clocksource clocksource_ji
> * subtraction of non 64 bit counters
> * @mult: cycle to nanosecond multiplier
> * @shift: cycle to nanosecond divisor (power of two)
> - * @update_callback: called when safe to alter clocksource values
> * @is_continuous: defines if clocksource is free-running.
> * @cycle_interval: Used internally by timekeeping core, please ignore.
> * @xtime_interval: Used internally by timekeeping core, please ignore.
> @@ -73,7 +72,6 @@ struct clocksource {
> cycle_t mask;
> u32 mult;
> u32 shift;
> - int (*update_callback)(void);
> int is_continuous;
>
> /* timekeeping specific data, ignore */
>

Other then the top bit I don't have an issue w/ this.

thanks
-john