diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-06-25 12:36:55 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-06-25 12:36:55 +0200 |
commit | f6477cc76c73833a56e97f1fafc36a7ca92927e5 (patch) | |
tree | 9b4ca3d9fa63ea001d516834c8b2707094f3f711 /arch/x86/kernel/tsc_32.c | |
parent | fd2c17e1777d46cff14c25ea774a4d17459d188a (diff) | |
parent | 543cf4cb3fe6f6cae3651ba918b9c56200b257d0 (diff) |
Merge branch 'linus' into x86/timers
Diffstat (limited to 'arch/x86/kernel/tsc_32.c')
-rw-r--r-- | arch/x86/kernel/tsc_32.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/arch/x86/kernel/tsc_32.c b/arch/x86/kernel/tsc_32.c index ac8b85e1893..774a5a83c29 100644 --- a/arch/x86/kernel/tsc_32.c +++ b/arch/x86/kernel/tsc_32.c @@ -14,7 +14,10 @@ #include "mach_timer.h" -static int tsc_disabled; +/* native_sched_clock() is called before tsc_init(), so + we must start with the TSC soft disabled to prevent + erroneous rdtsc usage on !cpu_has_tsc processors */ +static int tsc_disabled = -1; /* * On some systems the TSC frequency does not @@ -401,25 +404,20 @@ void __init tsc_init(void) { int cpu; - if (!cpu_has_tsc || tsc_disabled) { - /* Disable the TSC in case of !cpu_has_tsc */ - tsc_disabled = 1; + if (!cpu_has_tsc || tsc_disabled > 0) return; - } cpu_khz = calculate_cpu_khz(); tsc_khz = cpu_khz; if (!cpu_khz) { mark_tsc_unstable("could not calculate TSC khz"); - /* - * We need to disable the TSC completely in this case - * to prevent sched_clock() from using it. - */ - tsc_disabled = 1; return; } + /* now allow native_sched_clock() to use rdtsc */ + tsc_disabled = 0; + printk("Detected %lu.%03lu MHz processor.\n", (unsigned long)cpu_khz / 1000, (unsigned long)cpu_khz % 1000); |