diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 2 | ||||
| -rw-r--r-- | Documentation/x86/x86_64/boot-options.txt | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/tsc.c | 18 |
3 files changed, 4 insertions, 20 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 533ff5c68970..5aed30cd0350 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2835,8 +2835,6 @@ nosync [HW,M68K] Disables sync negotiation for all devices. - notsc [BUGS=X86-32] Disable Time Stamp Counter - nowatchdog [KNL] Disable both lockup detectors, i.e. soft-lockup and NMI watchdog (hard-lockup). diff --git a/Documentation/x86/x86_64/boot-options.txt b/Documentation/x86/x86_64/boot-options.txt index 8d109ef67ab6..66114ab4f9fe 100644 --- a/Documentation/x86/x86_64/boot-options.txt +++ b/Documentation/x86/x86_64/boot-options.txt @@ -92,9 +92,7 @@ APICs Timing notsc - Don't use the CPU time stamp counter to read the wall time. - This can be used to work around timing problems on multiprocessor systems - with not properly synchronized CPUs. + Deprecated, use tsc=unstable instead. nohpet Don't use the HPET timer. diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 74392d9d51e0..186395041725 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -38,11 +38,6 @@ EXPORT_SYMBOL(tsc_khz); */ static int __read_mostly tsc_unstable; -/* native_sched_clock() is called before tsc_init(), so - we must start with the TSC soft disabled to prevent - erroneous rdtsc usage on !boot_cpu_has(X86_FEATURE_TSC) processors */ -static int __read_mostly tsc_disabled = -1; - static DEFINE_STATIC_KEY_FALSE(__use_tsc); int tsc_clocksource_reliable; @@ -248,8 +243,7 @@ EXPORT_SYMBOL_GPL(check_tsc_unstable); #ifdef CONFIG_X86_TSC int __init notsc_setup(char *str) { - pr_warn("Kernel compiled with CONFIG_X86_TSC, cannot disable TSC completely\n"); - tsc_disabled = 1; + mark_tsc_unstable("boot parameter notsc"); return 1; } #else @@ -1307,7 +1301,7 @@ unreg: static int __init init_tsc_clocksource(void) { - if (!boot_cpu_has(X86_FEATURE_TSC) || tsc_disabled > 0 || !tsc_khz) + if (!boot_cpu_has(X86_FEATURE_TSC) || !tsc_khz) return 0; if (tsc_unstable) @@ -1414,12 +1408,6 @@ void __init tsc_init(void) set_cyc2ns_scale(tsc_khz, cpu, cyc); } - if (tsc_disabled > 0) - return; - - /* now allow native_sched_clock() to use rdtsc */ - - tsc_disabled = 0; static_branch_enable(&__use_tsc); if (!no_sched_irq_time) @@ -1455,7 +1443,7 @@ unsigned long calibrate_delay_is_known(void) int constant_tsc = cpu_has(&cpu_data(cpu), X86_FEATURE_CONSTANT_TSC); const struct cpumask *mask = topology_core_cpumask(cpu); - if (tsc_disabled || !constant_tsc || !mask) + if (!constant_tsc || !mask) return 0; sibling = cpumask_any_but(mask, cpu); |