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From: Peter Zijlstra <peterz@infradead.org>
To: kan.liang@linux.intel.com
Cc: mingo@redhat.com, linux-kernel@vger.kernel.org,
	namhyung@kernel.org, eranian@google.com, ak@linux.intel.com,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] perf/x86/intel/ds: Fix the conversion from TSC to perf time
Date: Mon, 23 Jan 2023 21:39:25 +0100	[thread overview]
Message-ID: <Y87wfaMJ2HLchgap@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230123172027.125385-1-kan.liang@linux.intel.com>

On Mon, Jan 23, 2023 at 09:20:27AM -0800, kan.liang@linux.intel.com wrote:
> The TSC unstable case seems to be some corner cases (e.g., due to broken
> BIOS). This patch doesn't support the conversion when the TSC is
> unstable. The TSC in a PEBS record will be dropped and fallback to the
> software perf time provided by the generic code.

:-(

You're saying there's modern systems (PEBS timestamps are fairly new)
that trigger unstable TSC ?

What systems in specific have you observed this on -- we really need to
name and shame them, this is fully unacceptable.

  reply	other threads:[~2023-01-23 20:41 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-23 17:20 [PATCH] perf/x86/intel/ds: Fix the conversion from TSC to perf time kan.liang
2023-01-23 20:39 ` Peter Zijlstra [this message]
2023-01-23 21:34   ` Liang, Kan

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