Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > linux.kernel > #1588833
| From | Paolo Bonzini <pbonzini@redhat.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: tip.today - scheduler bam boom crash (cpu hotplug) |
| Date | 2017-02-27 18:30 +0100 |
| Message-ID | <tfxhv-jQ-9@gated-at.bofh.it> (permalink) |
| References | (6 earlier) <tfvz5-7vd-45@gated-at.bofh.it> <tfvz5-7vd-43@gated-at.bofh.it> <tfwls-86h-17@gated-at.bofh.it> <tfwls-86h-15@gated-at.bofh.it> <tfwv8-8at-13@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 27/02/2017 17:36, Peter Zijlstra wrote:
> diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
> index 4e95b2e0d95f..bc3bbb6a8ab0 100644
> --- a/arch/x86/kernel/cpu/amd.c
> +++ b/arch/x86/kernel/cpu/amd.c
> @@ -555,10 +555,8 @@ static void early_init_amd(struct cpuinfo_x86 *c)
> if (c->x86_power & (1 << 8)) {
> set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
> set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
> - if (check_tsc_unstable())
> - clear_sched_clock_stable();
> } else {
> - clear_sched_clock_stable();
> + mark_tsc_unstable("not invariant");
> }
>
> /* Bit 12 of 8000_0007 edx is accumulated power mechanism. */
> diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c
> index 2c234a6d94c4..0fdff183aa30 100644
> --- a/arch/x86/kernel/cpu/centaur.c
> +++ b/arch/x86/kernel/cpu/centaur.c
> @@ -105,7 +105,7 @@ static void early_init_centaur(struct cpuinfo_x86 *c)
> set_cpu_cap(c, X86_FEATURE_SYSENTER32);
> #endif
>
> - clear_sched_clock_stable();
> + mark_tsc_unstable("not invariant");
> }
>
> static void init_centaur(struct cpuinfo_x86 *c)
> diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
> index f07005e6f461..2b7ff648ea25 100644
> --- a/arch/x86/kernel/cpu/common.c
> +++ b/arch/x86/kernel/cpu/common.c
> @@ -86,7 +86,7 @@ static void default_init(struct cpuinfo_x86 *c)
> strcpy(c->x86_model_id, "386");
> }
> #endif
> - clear_sched_clock_stable();
> + mark_tsc_unstable("not invariant");
> }
>
> static const struct cpu_dev default_cpu = {
> @@ -1076,7 +1076,7 @@ static void identify_cpu(struct cpuinfo_x86 *c)
> if (this_cpu->c_init)
> this_cpu->c_init(c);
> else
> - clear_sched_clock_stable();
> + mark_tsc_unstable("not invariant");
>
> /* Disable the PN if appropriate */
> squash_the_stupid_serial_number(c);
> diff --git a/arch/x86/kernel/cpu/cyrix.c b/arch/x86/kernel/cpu/cyrix.c
> index 47416f959a48..35057d67e864 100644
> --- a/arch/x86/kernel/cpu/cyrix.c
> +++ b/arch/x86/kernel/cpu/cyrix.c
> @@ -184,7 +184,7 @@ static void early_init_cyrix(struct cpuinfo_x86 *c)
> set_cpu_cap(c, X86_FEATURE_CYRIX_ARR);
> break;
> }
> - clear_sched_clock_stable();
> + mark_tsc_unstable("not invariant");
> }
>
> static void init_cyrix(struct cpuinfo_x86 *c)
> diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
> index 017ecd3bb553..e0e192e43a4c 100644
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -161,10 +161,8 @@ static void early_init_intel(struct cpuinfo_x86 *c)
> if (c->x86_power & (1 << 8)) {
> set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
> set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
> - if (check_tsc_unstable())
> - clear_sched_clock_stable();
> } else {
> - clear_sched_clock_stable();
> + mark_tsc_unstable("not invariant");
> }
>
> /* Penwell and Cloverview have the TSC which doesn't sleep on S3 */
Doh, these are called _before_ kvmclock_init. But perhaps they can all
be replaced by something like this:
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 2724dc82f992..3080b6877190 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1398,6 +1398,9 @@ void __init tsc_init(void)
use_tsc_delay();
+ if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+ mark_tsc_unstable("not invariant");
+
if (unsynchronized_tsc())
mark_tsc_unstable("TSCs unsynchronized");
The rest seems nice.
Paolo
Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Re: tip.today - scheduler bam boom crash (cpu hotplug) Wanpeng Li <kernellwp@gmail.com> - 2017-02-27 13:40 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Peter Zijlstra <peterz@infradead.org> - 2017-02-27 13:50 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Paolo Bonzini <pbonzini@redhat.com> - 2017-02-27 14:00 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Paolo Bonzini <pbonzini@redhat.com> - 2017-02-27 16:40 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Paolo Bonzini <pbonzini@redhat.com> - 2017-02-27 17:30 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Peter Zijlstra <peterz@infradead.org> - 2017-02-27 17:40 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Paolo Bonzini <pbonzini@redhat.com> - 2017-02-27 18:30 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Thomas Gleixner <tglx@linutronix.de> - 2017-02-27 19:10 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Paolo Bonzini <pbonzini@redhat.com> - 2017-02-27 20:10 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Peter Zijlstra <peterz@infradead.org> - 2017-02-28 00:00 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Wanpeng Li <kernellwp@gmail.com> - 2017-02-28 03:00 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Peter Zijlstra <peterz@infradead.org> - 2017-02-28 09:10 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Wanpeng Li <kernellwp@gmail.com> - 2017-02-28 09:20 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Peter Zijlstra <peterz@infradead.org> - 2017-02-27 17:50 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Peter Zijlstra <peterz@infradead.org> - 2017-02-27 23:50 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Wanpeng Li <kernellwp@gmail.com> - 2017-02-27 15:00 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Peter Zijlstra <peterz@infradead.org> - 2017-02-27 15:50 +0100
Re: tip.today - scheduler bam boom crash (cpu hotplug) Paolo Bonzini <pbonzini@redhat.com> - 2017-02-27 16:10 +0100
csiph-web