diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-08-24 14:52:06 -0400 |
---|---|---|
committer | H. Peter Anvin <hpa@zytor.com> | 2008-08-24 20:16:28 -0400 |
commit | 060700b571717c997a2ea5e2049b848fa248ee13 (patch) | |
tree | 46bdd7a9eb5cbb95458fc9839270d2e503fa6c4c /arch/x86/kernel/tsc.c | |
parent | 8735728ef8dc935c4fb351f913758fdbb62c308d (diff) |
x86: do not enable TSC notifier if we don't need it
Impact: crash on non-TSC-equipped CPUs
Don't enable the TSC notifier if we *either*:
1. don't have a CPU, or
2. have a CPU with constant TSC.
In either of those cases, the notifier is either damaging (1) or useless(2).
From: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel/tsc.c')
-rw-r--r-- | arch/x86/kernel/tsc.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 46af71676738..9bed5cae4bdc 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c | |||
@@ -325,6 +325,10 @@ static struct notifier_block time_cpufreq_notifier_block = { | |||
325 | 325 | ||
326 | static int __init cpufreq_tsc(void) | 326 | static int __init cpufreq_tsc(void) |
327 | { | 327 | { |
328 | if (!cpu_has_tsc) | ||
329 | return 0; | ||
330 | if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC)) | ||
331 | return 0; | ||
328 | cpufreq_register_notifier(&time_cpufreq_notifier_block, | 332 | cpufreq_register_notifier(&time_cpufreq_notifier_block, |
329 | CPUFREQ_TRANSITION_NOTIFIER); | 333 | CPUFREQ_TRANSITION_NOTIFIER); |
330 | return 0; | 334 | return 0; |