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authorLinus Torvalds <torvalds@linux-foundation.org>2008-04-07 13:14:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-07 13:14:37 -0700
commit950b0d28378c4ee63a30dad732a8319c8a41c95d (patch)
treee7e8a41ac5b11b650180a84c92f517d15907a9ba /arch
parent2557a933b795c1988c721ebb871cd735128bb9cb (diff)
parent871de939030c903fd5ed50a7c4c88e02998e1cbc (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86: x86: fix 64-bit asm NOPS for CONFIG_GENERIC_CPU x86: fix call to set_cyc2ns_scale() from time_cpufreq_notifier() revert "x86: tsc prevent time going backwards"
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/tsc_32.c19
-rw-r--r--arch/x86/kernel/tsc_64.c27
2 files changed, 6 insertions, 40 deletions
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c
index d7498b34c8e9..c2241e04ea5f 100644
--- a/arch/x86/kernel/tsc_32.c
+++ b/arch/x86/kernel/tsc_32.c
@@ -256,9 +256,7 @@ time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, void *data)
ref_freq, freq->new);
if (!(freq->flags & CPUFREQ_CONST_LOOPS)) {
tsc_khz = cpu_khz;
- preempt_disable();
- set_cyc2ns_scale(cpu_khz, smp_processor_id());
- preempt_enable();
+ set_cyc2ns_scale(cpu_khz, freq->cpu);
/*
* TSC based sched_clock turns
* to junk w/ cpufreq
@@ -287,27 +285,14 @@ core_initcall(cpufreq_tsc);
/* clock source code */
static unsigned long current_tsc_khz = 0;
-static struct clocksource clocksource_tsc;
-/*
- * We compare the TSC to the cycle_last value in the clocksource
- * structure to avoid a nasty time-warp issue. This can be observed in
- * a very small window right after one CPU updated cycle_last under
- * xtime lock and the other CPU reads a TSC value which is smaller
- * than the cycle_last reference value due to a TSC which is slighty
- * behind. This delta is nowhere else observable, but in that case it
- * results in a forward time jump in the range of hours due to the
- * unsigned delta calculation of the time keeping core code, which is
- * necessary to support wrapping clocksources like pm timer.
- */
static cycle_t read_tsc(void)
{
cycle_t ret;
rdtscll(ret);
- return ret >= clocksource_tsc.cycle_last ?
- ret : clocksource_tsc.cycle_last;
+ return ret;
}
static struct clocksource clocksource_tsc = {
diff --git a/arch/x86/kernel/tsc_64.c b/arch/x86/kernel/tsc_64.c
index 01fc9f0c39e2..d3bebaaad842 100644
--- a/arch/x86/kernel/tsc_64.c
+++ b/arch/x86/kernel/tsc_64.c
@@ -11,7 +11,6 @@
#include <asm/hpet.h>
#include <asm/timex.h>
#include <asm/timer.h>
-#include <asm/vgtod.h>
static int notsc __initdata = 0;
@@ -149,9 +148,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
mark_tsc_unstable("cpufreq changes");
}
- preempt_disable();
- set_cyc2ns_scale(tsc_khz_ref, smp_processor_id());
- preempt_enable();
+ set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
return 0;
}
@@ -291,34 +288,18 @@ int __init notsc_setup(char *s)
__setup("notsc", notsc_setup);
-static struct clocksource clocksource_tsc;
-/*
- * We compare the TSC to the cycle_last value in the clocksource
- * structure to avoid a nasty time-warp. This can be observed in a
- * very small window right after one CPU updated cycle_last under
- * xtime/vsyscall_gtod lock and the other CPU reads a TSC value which
- * is smaller than the cycle_last reference value due to a TSC which
- * is slighty behind. This delta is nowhere else observable, but in
- * that case it results in a forward time jump in the range of hours
- * due to the unsigned delta calculation of the time keeping core
- * code, which is necessary to support wrapping clocksources like pm
- * timer.
- */
+/* clock source code: */
static cycle_t read_tsc(void)
{
cycle_t ret = (cycle_t)get_cycles();
-
- return ret >= clocksource_tsc.cycle_last ?
- ret : clocksource_tsc.cycle_last;
+ return ret;
}
static cycle_t __vsyscall_fn vread_tsc(void)
{
cycle_t ret = (cycle_t)vget_cycles();
-
- return ret >= __vsyscall_gtod_data.clock.cycle_last ?
- ret : __vsyscall_gtod_data.clock.cycle_last;
+ return ret;
}
static struct clocksource clocksource_tsc = {