Drop.
Signed-Off-By: Daniel Walker <[email protected]>
---
arch/i386/kernel/tsc.c | 51 +++++++++++++++++++++++++++++---------------
include/linux/clocksource.h | 11 ++++++---
kernel/timer.c | 3 ++
3 files changed, 45 insertions(+), 20 deletions(-)
Index: linux-2.6.19/arch/i386/kernel/tsc.c
===================================================================
--- linux-2.6.19.orig/arch/i386/kernel/tsc.c
+++ linux-2.6.19/arch/i386/kernel/tsc.c
@@ -60,6 +60,12 @@ static inline int check_tsc_unstable(voi
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:
@@ -289,6 +295,7 @@ 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)
{
@@ -306,28 +313,38 @@ static struct clocksource clocksource_ts
.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,
};
-void mark_tsc_unstable(void)
+static int tsc_update_callback(void)
{
- 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;
+ int change = 0;
+
+ /* check to see if we should switch to the safe clocksource: */
+ if (clocksource_tsc.rating != 0 && check_tsc_unstable()) {
+ clocksource_tsc.rating = 0;
+ clocksource_reselect();
+ change = 1;
+ }
+
+ /* 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);
- tsc_unstable = 1;
+ mark_tsc_unstable();
return 0;
}
@@ -399,12 +416,11 @@ __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) {
- /* assume multi socket systems are not synchronized: */
- if (num_possible_cpus() > 1)
- tsc_unstable = 1;
- }
- return tsc_unstable;
+ if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
+ return 0;
+
+ /* assume multi socket systems are not synchronized: */
+ return num_possible_cpus() > 1;
}
/*
@@ -433,7 +449,8 @@ static int __init init_tsc_clocksource(v
/* check blacklist */
dmi_check_system(bad_tsc_dmi_table);
- unsynchronized_tsc();
+ if (unsynchronized_tsc()) /* mark unstable if unsynced */
+ mark_tsc_unstable();
check_geode_tsc_reliable();
current_tsc_khz = tsc_khz;
clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
Index: linux-2.6.19/include/linux/clocksource.h
===================================================================
--- linux-2.6.19.orig/include/linux/clocksource.h
+++ linux-2.6.19/include/linux/clocksource.h
@@ -44,6 +44,7 @@ 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
* @vread: vsyscall based read
* @cycle_interval: Used internally by timekeeping core, please ignore.
@@ -57,6 +58,7 @@ struct clocksource {
cycle_t mask;
u32 mult;
u32 shift;
+ int (*update_callback)(void);
unsigned long flags;
cycle_t (*vread)(void);
@@ -184,9 +186,9 @@ static inline void clocksource_calculate
/* used to install a new clocksource */
-extern int clocksource_register(struct clocksource*);
-extern struct clocksource* clocksource_get_next(void);
-extern void clocksource_change_rating(struct clocksource *cs, int rating);
+int clocksource_register(struct clocksource*);
+void clocksource_reselect(void);
+struct clocksource* clocksource_get_next(void);
#ifdef CONFIG_GENERIC_TIME_VSYSCALL
extern void update_vsyscall(struct timespec *ts, struct clocksource *c);
@@ -196,4 +198,7 @@ static inline void update_vsyscall(struc
}
#endif
+#define clocksource_reselect() clocksource_change_rating(&clocksource_tsc, clocksource_tsc.rating)
+extern void clocksource_change_rating(struct clocksource *cs, int rating);
+
#endif /* _LINUX_CLOCKSOURCE_H */
Index: linux-2.6.19/kernel/timer.c
===================================================================
--- linux-2.6.19.orig/kernel/timer.c
+++ linux-2.6.19/kernel/timer.c
@@ -893,6 +893,8 @@ 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;
}
@@ -959,6 +961,7 @@ void __init timekeeping_init(void)
write_sequnlock_irqrestore(&xtime_lock, flags);
}
+
/* flag for if timekeeping is suspended */
static int timekeeping_suspended;
/* time in seconds when suspend began */
--
-
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