From: Peter Zijlstra <peterz@infradead.org>
To: Arjan van de Ven <arjan@linux.intel.com>,
Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Arjan van de Ven <arjan@linux.intel.com>,
feng.tang@intel.com
Subject: Re: [PATCH] x86/tsc: Have tsc=recalibrate override things
Date: Mon, 30 Oct 2023 17:03:44 +0100 [thread overview]
Message-ID: <20231030160344.GA19106@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20231030160050.GA15024@noisy.programming.kicks-ass.net>
On Mon, Oct 30, 2023 at 05:00:50PM +0100, Peter Zijlstra wrote:
> Hi,
>
> My brand-spanking new SPR supermicro workstation was reporting NTP
> failures:
>
> Oct 30 13:00:26 spr ntpd[3517]: CLOCK: kernel reports TIME_ERROR: 0x41: Clock Unsynchronized
> Oct 30 13:00:58 spr ntpd[3517]: CLOCK: time stepped by 32.316775
> Oct 30 13:00:58 spr ntpd[3517]: CLOCK: frequency error 41699 PPM exceeds tolerance 500 PPM
>
> CPUID provides:
>
> Time Stamp Counter/Core Crystal Clock Information (0x15):
> TSC/clock ratio = 200/2
> nominal core crystal clock = 25000000 Hz
> Processor Frequency Information (0x16):
> Core Base Frequency (MHz) = 0x9c4 (2500)
> Core Maximum Frequency (MHz) = 0x12c0 (4800)
> Bus (Reference) Frequency (MHz) = 0x64 (100)
>
> and the kernel believes this. Since commit a7ec817d5542 ("x86/tsc: Add
> option to force frequency recalibration with HW timer") there is the
> tsc=recalibrate option, which forces the recalibrate.
>
> This duely reports:
>
> Oct 30 12:42:39 spr kernel: tsc: Warning: TSC freq calibrated by CPUID/MSR differs from what is calibrated by HW timer, please check with vendor!!
> Oct 30 12:42:39 spr kernel: tsc: Previous calibrated TSC freq: 2500.000 MHz
> Oct 30 12:42:39 spr kernel: tsc: TSC freq recalibrated by [HPET]: 2399.967 MHz
Arjan, can you please escalate this to our supermicro contact?
next prev parent reply other threads:[~2023-10-30 16:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-30 16:00 [PATCH] x86/tsc: Have tsc=recalibrate override things Peter Zijlstra
2023-10-30 16:03 ` Peter Zijlstra [this message]
2023-10-30 16:04 ` Peter Zijlstra
2023-11-01 11:16 ` [PATCH v2] " Peter Zijlstra
2023-11-01 13:17 ` Feng Tang
2023-11-01 17:50 ` Peter Zijlstra
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