From: Thomas Gleixner <tglx@linutronix.de>
To: kan.liang@linux.intel.com, jstultz@google.com,
peterz@infradead.org, mingo@redhat.com,
linux-kernel@vger.kernel.org
Cc: sboyd@kernel.org, eranian@google.com, namhyung@kernel.org,
ak@linux.intel.com, adrian.hunter@intel.com,
Kan Liang <kan.liang@linux.intel.com>,
Ravi Bangoria <ravi.bangoria@amd.com>
Subject: Re: [RFC PATCH V2 4/9] perf/x86: Enable post-processing monotonic raw conversion
Date: Tue, 14 Feb 2023 21:02:23 +0100 [thread overview]
Message-ID: <875yc4rp68.ffs@tglx> (raw)
In-Reply-To: <20230213190754.1836051-5-kan.liang@linux.intel.com>
Kan!
On Mon, Feb 13 2023 at 11:07, kan liang wrote:
> From: Kan Liang <kan.liang@linux.intel.com>
> + } else if (perf_event_hw_time(event)) {
> + struct ktime_conv mono;
> +
> + userpg->cap_user_time_mono_raw = 1;
> + ktime_get_fast_mono_raw_conv(&mono);
What guarantees that the clocksource used by the timekeeping core is
actually TSC? Nothing at all. You cannot make assumptions here.
Thanks,
tglx
next prev parent reply other threads:[~2023-02-14 20:02 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-13 19:07 [RFC PATCH V2 0/9] Convert TSC to monotonic raw clock for PEBS kan.liang
2023-02-13 19:07 ` [RFC PATCH V2 1/9] timekeeping: Expose the conversion information of monotonic raw kan.liang
2023-02-13 19:28 ` John Stultz
2023-02-13 19:07 ` [RFC PATCH V2 2/9] perf: Extend ABI to support post-processing monotonic raw conversion kan.liang
2023-02-13 19:37 ` John Stultz
2023-02-13 21:40 ` Liang, Kan
2023-02-13 22:22 ` John Stultz
2023-02-14 10:43 ` Peter Zijlstra
2023-02-14 17:46 ` Liang, Kan
2023-02-14 19:37 ` John Stultz
2023-02-14 20:09 ` Liang, Kan
2023-02-14 20:21 ` John Stultz
2023-03-12 20:50 ` Andi Kleen
2023-02-14 19:34 ` John Stultz
2023-02-14 14:51 ` Liang, Kan
2023-02-14 17:00 ` Liang, Kan
2023-02-14 20:11 ` John Stultz
2023-02-14 20:38 ` Liang, Kan
2023-02-17 23:11 ` John Stultz
2023-03-08 18:44 ` Liang, Kan
2023-03-09 1:17 ` John Stultz
2023-03-09 16:56 ` Liang, Kan
2023-03-11 5:55 ` John Stultz
2023-03-13 21:19 ` Liang, Kan
2023-03-18 6:02 ` John Stultz
2023-03-21 15:26 ` Liang, Kan
2023-02-14 19:52 ` John Stultz
2023-02-13 19:07 ` [RFC PATCH V2 3/9] perf/x86: Factor out x86_pmu_sample_preload() kan.liang
2023-02-13 19:07 ` [RFC PATCH V2 4/9] perf/x86: Enable post-processing monotonic raw conversion kan.liang
2023-02-14 20:02 ` Thomas Gleixner [this message]
2023-02-14 20:21 ` Liang, Kan
2023-02-14 20:55 ` Thomas Gleixner
2023-03-21 15:38 ` Liang, Kan
2023-02-13 19:07 ` [RFC PATCH V2 5/9] perf/x86/intel: Enable large PEBS for monotonic raw kan.liang
2023-02-13 19:07 ` [RFC PATCH V2 6/9] tools headers UAPI: Sync linux/perf_event.h with the kernel sources kan.liang
2023-02-13 19:07 ` [RFC PATCH V2 7/9] perf session: Support the monotonic raw clock conversion information kan.liang
2023-02-13 19:07 ` [RFC PATCH V2 8/9] perf evsel, tsc: Support the monotonic raw clock conversion kan.liang
2023-02-13 19:07 ` [RFC PATCH V2 9/9] perf evsel: Enable post-processing monotonic raw conversion by default kan.liang
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