Re: [PATCH] x86/tsc: mark tsc reliable for qualified platforms

2021-03-07 Thread Feng Tang
On Wed, Mar 03, 2021 at 10:51:31PM +0800, Thomas Gleixner wrote: > On Tue, Mar 02 2021 at 10:52, Feng Tang wrote: > > There are cases that tsc clocksource are wrongly judged as unstable by > > clocksource watchdogs like hpet, acpi_pm or 'refined-jiffies'. While > > there is hardly a general

Re: [PATCH] x86/tsc: mark tsc reliable for qualified platforms

2021-03-03 Thread Thomas Gleixner
On Tue, Mar 02 2021 at 10:52, Feng Tang wrote: > There are cases that tsc clocksource are wrongly judged as unstable by > clocksource watchdogs like hpet, acpi_pm or 'refined-jiffies'. While > there is hardly a general reliable way to check the validity of a > watchdog, and to protect the innocent

Re: [PATCH] x86/tsc: mark tsc reliable for qualified platforms

2021-03-02 Thread Feng Tang
On Tue, Mar 02, 2021 at 10:14:01AM +0100, Peter Zijlstra wrote: > On Tue, Mar 02, 2021 at 10:52:52AM +0800, Feng Tang wrote: > > @@ -1193,6 +1193,17 @@ static void __init check_system_tsc_reliable(void) > > #endif > > if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) > >

Re: [PATCH] x86/tsc: mark tsc reliable for qualified platforms

2021-03-02 Thread Peter Zijlstra
On Tue, Mar 02, 2021 at 10:52:52AM +0800, Feng Tang wrote: > @@ -1193,6 +1193,17 @@ static void __init check_system_tsc_reliable(void) > #endif > if (boot_cpu_has(X86_FEATURE_TSC_RELIABLE)) > tsc_clocksource_reliable = 1; > + > + /* > + * Ideally the socket number

[PATCH] x86/tsc: mark tsc reliable for qualified platforms

2021-03-01 Thread Feng Tang
There are cases that tsc clocksource are wrongly judged as unstable by clocksource watchdogs like hpet, acpi_pm or 'refined-jiffies'. While there is hardly a general reliable way to check the validity of a watchdog, and to protect the innocent tsc, Thomas Gleixner proposed [1]: "I'm inclined to