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| Started by | Prarit Bhargava <prarit@redhat.com> |
|---|---|
| First post | 2016-09-15 17:10 +0200 |
| Last post | 2016-09-15 19:50 +0200 |
| Articles | 5 — 3 participants |
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[PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist Prarit Bhargava <prarit@redhat.com> - 2016-09-15 17:10 +0200
Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist Peter Zijlstra <peterz@infradead.org> - 2016-09-15 17:20 +0200
RE: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist "Brown, Len" <len.brown@intel.com> - 2016-09-15 18:10 +0200
Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist Peter Zijlstra <peterz@infradead.org> - 2016-09-15 19:50 +0200
Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist Prarit Bhargava <prarit@redhat.com> - 2016-09-15 19:50 +0200
| From | Prarit Bhargava <prarit@redhat.com> |
|---|---|
| Date | 2016-09-15 17:10 +0200 |
| Subject | [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist |
| Message-ID | <shGsx-ar-3@gated-at.bofh.it> |
In commit aa297292d708 ("x86/tsc: Enumerate SKL cpu_khz and tsc_khz via
CPUID"), the kernel added support for Intel processors which had
a different CPU base-frequency and TSC frequency.
The turbostat utility has been updated with KBL and SKX processors,
and they should also be added to the crystal_khz white list.
For example, on INTEL_FAM6_KABYLAKE_MOBILE native_calibrate_tsc() returns 0 MHz
for tsc_khz and after this patch native_calibrate_tsc() returns 1608 MHz.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Rafael Aquini <aquini@redhat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Len Brown <len.brown@intel.com>
Cc: lenb@kernel.org
---
arch/x86/kernel/tsc.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 2344758ba8a3..dfa70a8867dc 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -689,11 +689,18 @@ unsigned long native_calibrate_tsc(void)
switch (boot_cpu_data.x86_model) {
case INTEL_FAM6_SKYLAKE_MOBILE:
case INTEL_FAM6_SKYLAKE_DESKTOP:
+ case INTEL_FAM6_KABYLAKE_MOBILE:
+ case INTEL_FAM6_KABYLAKE_DESKTOP:
crystal_khz = 24000; /* 24.0 MHz */
break;
+ case INTEL_FAM6_SKYLAKE_X:
+ crystal_khz = 24000; /* 25.0 MHz */
+ break;
case INTEL_FAM6_ATOM_GOLDMONT:
crystal_khz = 19200; /* 19.2 MHz */
break;
+ default:
+ crystal_khz = 0;
}
}
--
1.7.9.3
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| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Date | 2016-09-15 17:20 +0200 |
| Subject | Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist |
| Message-ID | <shGCd-dP-9@gated-at.bofh.it> |
| In reply to | #1484279 |
On Thu, Sep 15, 2016 at 11:04:18AM -0400, Prarit Bhargava wrote:
> +++ b/arch/x86/kernel/tsc.c
> @@ -689,11 +689,18 @@ unsigned long native_calibrate_tsc(void)
> switch (boot_cpu_data.x86_model) {
> case INTEL_FAM6_SKYLAKE_MOBILE:
> case INTEL_FAM6_SKYLAKE_DESKTOP:
> + case INTEL_FAM6_KABYLAKE_MOBILE:
> + case INTEL_FAM6_KABYLAKE_DESKTOP:
> crystal_khz = 24000; /* 24.0 MHz */
> break;
> + case INTEL_FAM6_SKYLAKE_X:
> + crystal_khz = 24000; /* 25.0 MHz */
^^^ != ^^^^
did you mean to type: 25000 ?
> + break;
> case INTEL_FAM6_ATOM_GOLDMONT:
> crystal_khz = 19200; /* 19.2 MHz */
> break;
> + default:
> + crystal_khz = 0;
> }
> }
>
> --
> 1.7.9.3
>
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| From | "Brown, Len" <len.brown@intel.com> |
|---|---|
| Date | 2016-09-15 18:10 +0200 |
| Subject | RE: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist |
| Message-ID | <shHoC-Ln-17@gated-at.bofh.it> |
| In reply to | #1484279 |
> + crystal_khz = 24000; /* 25.0 MHz */ I guess I prefer no comment over an incorrect comment.
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| From | Peter Zijlstra <peterz@infradead.org> |
|---|---|
| Date | 2016-09-15 19:50 +0200 |
| Subject | Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist |
| Message-ID | <shIXo-1D5-47@gated-at.bofh.it> |
| In reply to | #1484369 |
On Thu, Sep 15, 2016 at 04:08:36PM +0000, Brown, Len wrote: > > + crystal_khz = 24000; /* 25.0 MHz */ > > I guess I prefer no comment over an incorrect comment. > From this I take it it should really have been 24 MHz and it could have joined the existing case. I assumed (ha!) that since it had a special separate case the comment was correct.
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| From | Prarit Bhargava <prarit@redhat.com> |
|---|---|
| Date | 2016-09-15 19:50 +0200 |
| Subject | Re: [PATCH 2/2] x86/tsc: Add additional Intel CPU models to crystal_khz whitelist |
| Message-ID | <shIXo-1D5-61@gated-at.bofh.it> |
| In reply to | #1484440 |
On 09/15/2016 01:43 PM, Peter Zijlstra wrote:
> On Thu, Sep 15, 2016 at 04:08:36PM +0000, Brown, Len wrote:
>>> + crystal_khz = 24000; /* 25.0 MHz */
>>
>> I guess I prefer no comment over an incorrect comment.
>>
>
> From this I take it it should really have been 24 MHz and it could have
> joined the existing case. I assumed (ha!) that since it had a special
> separate case the comment was correct.
AFAICT, it should be 25000. Len -- can you explicitly confirm that? The
turbostat code contains (tools/power/x86/turbostat/turbostat.c:3312)
case 0x55: /* SKX */
crystal_hz = 25000000; /* 25.0 MHz */
P.
>
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