From: Thomas Gleixner <tglx@linutronix.de>
To: "Liang, Kan" <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,
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 21:55:53 +0100 [thread overview]
Message-ID: <873578rmp2.ffs@tglx> (raw)
In-Reply-To: <4372ae84-76e2-8bae-b0ad-87102973df67@linux.intel.com>
On Tue, Feb 14 2023 at 15:21, Kan Liang wrote:
> On 2023-02-14 3:02 p.m., Thomas Gleixner wrote:
>>
>> What guarantees that the clocksource used by the timekeeping core is
>> actually TSC? Nothing at all. You cannot make assumptions here.
>>
>
> Yes, you are right.
> I will add a check to make sure the clocksource is TSC when perf does
> the conversion.
>
> Could you please comment on whether the patch is in the right direction?
> This V2 patch series expose the kernel internal conversion information
> into the user space. Is it OK for you?
Making the conversion info an ABI is suboptimal at best. I'm still
trying to wrap my brain around all of this. Will reply over there once
my confusion subsides.
Thanks,
tglx
next prev parent reply other threads:[~2023-02-14 20:55 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
2023-02-14 20:21 ` Liang, Kan
2023-02-14 20:55 ` Thomas Gleixner [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=873578rmp2.ffs@tglx \
--to=tglx@linutronix.de \
--cc=adrian.hunter@intel.com \
--cc=ak@linux.intel.com \
--cc=eranian@google.com \
--cc=jstultz@google.com \
--cc=kan.liang@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=namhyung@kernel.org \
--cc=peterz@infradead.org \
--cc=ravi.bangoria@amd.com \
--cc=sboyd@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox