diff options
| author | Andi Kleen <ak@suse.de> | 2005-04-16 15:25:05 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:25:05 -0700 |
| commit | c29601e9c1e7893d1755364e350c9188bd56d69f (patch) | |
| tree | 14813ddce4d8897b40cc8b3a2f76ace3ac58b36f /arch/x86_64/kernel/time.c | |
| parent | dc37db4d8cb376bb67c6357c50d707ced3d71c39 (diff) | |
| download | linux-c29601e9c1e7893d1755364e350c9188bd56d69f.tar.gz | |
[PATCH] x86_64: Support constantly ticking TSCs
On Intel Noconas the TSC ticks with a constant frequency. Don't scale the
factor used by udelay when cpufreq changes the frequency.
This generalizes an earlier patch by Intel for this.
Cc: <venkatesh.pallipadi@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/time.c')
| -rw-r--r-- | arch/x86_64/kernel/time.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c index 3bafe438fa7500..c7a1b50b4af34b 100644 --- a/arch/x86_64/kernel/time.c +++ b/arch/x86_64/kernel/time.c @@ -614,6 +614,9 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, struct cpufreq_freqs *freq = data; unsigned long *lpj, dummy; + if (cpu_has(&cpu_data[freq->cpu], X86_FEATURE_CONSTANT_TSC)) + return 0; + lpj = &dummy; if (!(freq->flags & CPUFREQ_CONST_LOOPS)) #ifdef CONFIG_SMP @@ -622,8 +625,6 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val, lpj = &boot_cpu_data.loops_per_jiffy; #endif - - if (!ref_freq) { ref_freq = freq->old; loops_per_jiffy_ref = *lpj; |