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Merge remote branch 'tip/x86/tsc' into fortglx/2.6.38/tip/x86/tsc

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Conflicts:
	Documentation/kernel-parameters.txt
This commit is contained in:
John Stultz 2010-12-02 16:47:52 -08:00
commit b0f969009f
2 changed files with 10 additions and 6 deletions
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9
Documentation/kernel-parameters.txt
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@ -2467,12 +2467,13 @@ and is between 256 and 4096 characters. It is defined in the file
to facilitate early boot debugging.
See also Documentation/trace/events.txt
tsc= Disable clocksource-must-verify flag for TSC.
tsc= Disable clocksource stability checks for TSC.
Format: <string>
[x86] reliable: mark tsc clocksource as reliable, this
disables clocksource verification at runtime.
Used to enable high-resolution timer mode on older
hardware, and in virtualized environment.
disables clocksource verification at runtime, as well
as the stability checks done at bootup. Used to enable
high-resolution timer mode on older hardware, and in
virtualized environment.
[x86] noirqtime: Do not use TSC to do irq accounting.
Used to run time disable IRQ_TIME_ACCOUNTING on any
platforms where RDTSC is slow and this accounting

7
arch/x86/kernel/tsc.c
View File

@ -872,6 +872,9 @@ __cpuinit int unsynchronized_tsc(void)
if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
return 0;
if (tsc_clocksource_reliable)
return 0;
/*
* Intel systems are normally all synchronized.
* Exceptions must mark TSC as unstable:
@ -879,10 +882,10 @@ __cpuinit int unsynchronized_tsc(void)
if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) {
/* assume multi socket systems are not synchronized: */
if (num_possible_cpus() > 1)
tsc_unstable = 1;
return 1;
}
return tsc_unstable;
return 0;
}
static void __init init_tsc_clocksource(void)