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[PATCH] clocksource: Remove the update callback

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The clocksource code allows direct updates of the rating of a given
clocksource now.  Change TSC unstable tracking to use this interface and
remove the update callback.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner 2007-02-16 01:27:42 -08:00 committed by Linus Torvalds
parent 877fe38029
commit 7e69f2b1ea
3 changed files with 17 additions and 37 deletions
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50
arch/i386/kernel/tsc.c
View File

@ -60,12 +60,6 @@ static inline int check_tsc_unstable(void)
return tsc_unstable;
}
void mark_tsc_unstable(void)
{
tsc_unstable = 1;
}
EXPORT_SYMBOL_GPL(mark_tsc_unstable);
/* Accellerators for sched_clock()
* convert from cycles(64bits) => nanoseconds (64bits)
* basic equation:
@ -295,7 +289,6 @@ 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)
{
@ -313,37 +306,28 @@ static struct clocksource clocksource_tsc = {
.mask = CLOCKSOURCE_MASK(64),
.mult = 0, /* to be set */
.shift = 22,
.update_callback = tsc_update_callback,
.flags = CLOCK_SOURCE_IS_CONTINUOUS |
CLOCK_SOURCE_MUST_VERIFY,
};
static int tsc_update_callback(void)
void mark_tsc_unstable(void)
{
int change = 0;
/* check to see if we should switch to the safe clocksource: */
if (clocksource_tsc.rating != 0 && check_tsc_unstable()) {
clocksource_change_rating(&clocksource_tsc, 0);
change = 1;
if (!tsc_unstable) {
tsc_unstable = 1;
/* Can be called before registration */
if (clocksource_tsc.mult)
clocksource_change_rating(&clocksource_tsc, 0);
else
clocksource_tsc.rating = 0;
}
/* only update if tsc_khz has changed: */
if (current_tsc_khz != tsc_khz) {
current_tsc_khz = tsc_khz;
clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
clocksource_tsc.shift);
change = 1;
}
return change;
}
EXPORT_SYMBOL_GPL(mark_tsc_unstable);
static int __init dmi_mark_tsc_unstable(struct dmi_system_id *d)
{
printk(KERN_NOTICE "%s detected: marking TSC unstable.\n",
d->ident);
mark_tsc_unstable();
tsc_unstable = 1;
return 0;
}
@ -415,11 +399,12 @@ __cpuinit int unsynchronized_tsc(void)
* Intel systems are normally all synchronized.
* Exceptions must mark TSC as unstable:
*/
if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
return 0;
/* assume multi socket systems are not synchronized: */
return num_possible_cpus() > 1;
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
/* assume multi socket systems are not synchronized: */
if (num_possible_cpus() > 1)
tsc_unstable = 1;
}
return tsc_unstable;
}
static int __init init_tsc_clocksource(void)
@ -429,8 +414,7 @@ static int __init init_tsc_clocksource(void)
/* check blacklist */
dmi_check_system(bad_tsc_dmi_table);
if (unsynchronized_tsc()) /* mark unstable if unsynced */
mark_tsc_unstable();
unsynchronized_tsc();
current_tsc_khz = tsc_khz;
clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
clocksource_tsc.shift);

2
include/linux/clocksource.h
View File

@ -44,7 +44,6 @@ typedef u64 cycle_t;
* 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
* @flags: flags describing special properties
* @cycle_interval: Used internally by timekeeping core, please ignore.
* @xtime_interval: Used internally by timekeeping core, please ignore.
@ -57,7 +56,6 @@ struct clocksource {
cycle_t mask;
u32 mult;
u32 shift;
int (*update_callback)(void);
unsigned long flags;
/* timekeeping specific data, ignore */

2
kernel/timer.c
View File

@ -848,8 +848,6 @@ static int change_clocksource(void)
printk(KERN_INFO "Time: %s clocksource has been installed.\n",
clock->name);
return 1;
} else if (clock->update_callback) {
return clock->update_callback();
}
return 0;
}