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* possible BUG: selftest about raw_skew failed
@ 2018-04-21 14:47 Jeffrin Thalakkottoor
  2018-04-26 21:28 ` Thomas Gleixner
  2018-04-26 21:33 ` John Stultz
  0 siblings, 2 replies; 6+ messages in thread
From: Jeffrin Thalakkottoor @ 2018-04-21 14:47 UTC (permalink / raw)
  To: shuah, keescook, anton, ccross, tony.luck, john.stultz, tglx, sboyd
  Cc: linux-kselftest, linux-kernel

hello,

failure of a test in selftest:timers

selftests: raw_skew
========================================
WARNING: ADJ_OFFSET in progress, this will cause inaccurate results
Estimating clock drift: 17.910(est) 16.820(act) [FAILED]
Bail out!
Pass 0 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
1..0
not ok 1..7 selftests:  raw_skew [FAIL]


To reproduce :

make -C tools/testing/selftests/timers/ run_tests




Linux debian 4.17.0-rc1+ #3 SMP Sat Apr 21 03:41:44 IST 2018 x86_64 GNU/Linux

GNU Make            4.2.1
Binutils            2.30
Util-linux          2.31.1
Mount                2.31.1
Linux C Library      2.27
Dynamic linker (ldd) 2.27
readlink: missing operand
Try 'readlink --help' for more information.
Procps              3.3.14
Kbd                  2.0.4
Console-tools        2.0.4
Sh-utils            8.28
Udev                238

-- 
software engineer
rajagiri school of engineering and technology

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: possible BUG: selftest about raw_skew failed
  2018-04-21 14:47 possible BUG: selftest about raw_skew failed Jeffrin Thalakkottoor
@ 2018-04-26 21:28 ` Thomas Gleixner
  2018-04-27  7:41   ` Miroslav Lichvar
  2018-04-26 21:33 ` John Stultz
  1 sibling, 1 reply; 6+ messages in thread
From: Thomas Gleixner @ 2018-04-26 21:28 UTC (permalink / raw)
  To: Jeffrin Thalakkottoor
  Cc: shuah, Kees Cook, anton, ccross, Tony Luck, John Stultz, sboyd,
	linux-kselftest, LKML, John Stultz, Miroslav Lichvar

On Sat, 21 Apr 2018, Jeffrin Thalakkottoor wrote:

Cc'ing John and Miroslav

> hello,
> 
> failure of a test in selftest:timers
> 
> selftests: raw_skew
> ========================================
> WARNING: ADJ_OFFSET in progress, this will cause inaccurate results
> Estimating clock drift: 17.910(est) 16.820(act) [FAILED]
> Bail out!
> Pass 0 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
> 1..0
> not ok 1..7 selftests:  raw_skew [FAIL]
> 
> 
> To reproduce :
> 
> make -C tools/testing/selftests/timers/ run_tests
> 
> 
> 
> 
> Linux debian 4.17.0-rc1+ #3 SMP Sat Apr 21 03:41:44 IST 2018 x86_64 GNU/Linux
> 
> GNU Make            4.2.1
> Binutils            2.30
> Util-linux          2.31.1
> Mount                2.31.1
> Linux C Library      2.27
> Dynamic linker (ldd) 2.27
> readlink: missing operand
> Try 'readlink --help' for more information.
> Procps              3.3.14
> Kbd                  2.0.4
> Console-tools        2.0.4
> Sh-utils            8.28
> Udev                238
> 
> -- 
> software engineer
> rajagiri school of engineering and technology
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: possible BUG: selftest about raw_skew failed
  2018-04-21 14:47 possible BUG: selftest about raw_skew failed Jeffrin Thalakkottoor
  2018-04-26 21:28 ` Thomas Gleixner
@ 2018-04-26 21:33 ` John Stultz
  2018-04-27 15:27   ` Jeffrin Thalakkottoor
  1 sibling, 1 reply; 6+ messages in thread
From: John Stultz @ 2018-04-26 21:33 UTC (permalink / raw)
  To: Jeffrin Thalakkottoor
  Cc: Shuah Khan, Kees Cook, Anton Vorontsov, Colin Cross, Tony Luck,
	Thomas Gleixner, sboyd, linux-kselftest, lkml

On Sat, Apr 21, 2018 at 7:47 AM, Jeffrin Thalakkottoor
<jeffrin@rajagiritech.edu.in> wrote:
> hello,
>
> failure of a test in selftest:timers
>
> selftests: raw_skew
> ========================================
> WARNING: ADJ_OFFSET in progress, this will cause inaccurate results
> Estimating clock drift: 17.910(est) 16.820(act) [FAILED]

So you're ignoring the warning above. If an ADJ_OFFSET operation is
going on, ntpd (or something similar) is changing the clock, which
will kill the estimated drift calculation.

-john

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: possible BUG: selftest about raw_skew failed
  2018-04-26 21:28 ` Thomas Gleixner
@ 2018-04-27  7:41   ` Miroslav Lichvar
  2018-04-27 15:28     ` Jeffrin Thalakkottoor
  0 siblings, 1 reply; 6+ messages in thread
From: Miroslav Lichvar @ 2018-04-27  7:41 UTC (permalink / raw)
  To: Jeffrin Thalakkottoor
  Cc: Thomas Gleixner, shuah, Kees Cook, anton, ccross, Tony Luck,
	John Stultz, sboyd, linux-kselftest, LKML

On Thu, Apr 26, 2018 at 11:28:29PM +0200, Thomas Gleixner wrote:
> On Sat, 21 Apr 2018, Jeffrin Thalakkottoor wrote:
> > selftests: raw_skew
> > ========================================
> > WARNING: ADJ_OFFSET in progress, this will cause inaccurate results
> > Estimating clock drift: 17.910(est) 16.820(act) [FAILED]

Was ntpd, systemd-timesyncd, or some other NTP/PTP daemon running
shortly before or during the test?

The warning indicates that the clock was slewed by adjtime() or
adjtimex(), which makes the measurement of the frequency less accurate
and the test may fail.

Maybe this test and other tests that measure the frequency of the
system clock should be modified to SKIP when adjtimex() returns a
non-zero offset (or the frequency changes during the test)? 

-- 
Miroslav Lichvar

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: possible BUG: selftest about raw_skew failed
  2018-04-26 21:33 ` John Stultz
@ 2018-04-27 15:27   ` Jeffrin Thalakkottoor
  0 siblings, 0 replies; 6+ messages in thread
From: Jeffrin Thalakkottoor @ 2018-04-27 15:27 UTC (permalink / raw)
  To: John Stultz
  Cc: Shuah Khan, Kees Cook, Anton Vorontsov, Colin Cross, Tony Luck,
	Thomas Gleixner, sboyd, linux-kselftest, lkml

I kind of ignored. i was not sure what that meant actually.

On Fri, Apr 27, 2018 at 3:03 AM, John Stultz <john.stultz@linaro.org> wrote:
> On Sat, Apr 21, 2018 at 7:47 AM, Jeffrin Thalakkottoor
> <jeffrin@rajagiritech.edu.in> wrote:
>> hello,
>>
>> failure of a test in selftest:timers
>>
>> selftests: raw_skew
>> ========================================
>> WARNING: ADJ_OFFSET in progress, this will cause inaccurate results
>> Estimating clock drift: 17.910(est) 16.820(act) [FAILED]
>
> So you're ignoring the warning above. If an ADJ_OFFSET operation is
> going on, ntpd (or something similar) is changing the clock, which
> will kill the estimated drift calculation.
>
> -john



-- 
software engineer
rajagiri school of engineering and technology

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: possible BUG: selftest about raw_skew failed
  2018-04-27  7:41   ` Miroslav Lichvar
@ 2018-04-27 15:28     ` Jeffrin Thalakkottoor
  0 siblings, 0 replies; 6+ messages in thread
From: Jeffrin Thalakkottoor @ 2018-04-27 15:28 UTC (permalink / raw)
  To: Miroslav Lichvar
  Cc: Thomas Gleixner, Shuah Khan, Kees Cook, anton, ccross, Tony Luck,
	John Stultz, sboyd, linux-kselftest, LKML

i think may be  systemd-timesyncd  was running.
anyway currently the status is as follows...

$systemctl status systemd-timesyncd.service
● systemd-timesyncd.service - Network Time Synchronization
   Loaded: loaded (/lib/systemd/system/systemd-timesyncd.service;
enabled; vendor preset: enabled)
   Active: active (running) since Fri 2018-04-27 19:26:16 IST; 1h 11min ago
     Docs: man:systemd-timesyncd.service(8)
 Main PID: 514 (systemd-timesyn)
   Status: "Synchronized to time server 123.108.200.124:123
(0.debian.pool.ntp.org)."
    Tasks: 2 (limit: 4382)
   Memory: 1.8M
   CGroup: /system.slice/systemd-timesyncd.service
           └─514 /lib/systemd/systemd-timesyncd
$

The test in the latest run show  "PASS"
see below...

selftests: raw_skew
========================================
Estimating clock drift: 26.836(est) 26.838(act) [OK]
Pass 0 Fail 0 Xfail 0 Xpass 0 Skip 0 Error 0
1..0
ok 1..7 selftests: raw_skew [PASS]



On Fri, Apr 27, 2018 at 1:11 PM, Miroslav Lichvar <mlichvar@redhat.com> wrote:
> On Thu, Apr 26, 2018 at 11:28:29PM +0200, Thomas Gleixner wrote:
>> On Sat, 21 Apr 2018, Jeffrin Thalakkottoor wrote:
>> > selftests: raw_skew
>> > ========================================
>> > WARNING: ADJ_OFFSET in progress, this will cause inaccurate results
>> > Estimating clock drift: 17.910(est) 16.820(act) [FAILED]
>
> Was ntpd, systemd-timesyncd, or some other NTP/PTP daemon running
> shortly before or during the test?
>
> The warning indicates that the clock was slewed by adjtime() or
> adjtimex(), which makes the measurement of the frequency less accurate
> and the test may fail.
>
> Maybe this test and other tests that measure the frequency of the
> system clock should be modified to SKIP when adjtimex() returns a
> non-zero offset (or the frequency changes during the test)?
>
> --
> Miroslav Lichvar



-- 
software engineer
rajagiri school of engineering and technology

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2018-04-27 15:28 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-21 14:47 possible BUG: selftest about raw_skew failed Jeffrin Thalakkottoor
2018-04-26 21:28 ` Thomas Gleixner
2018-04-27  7:41   ` Miroslav Lichvar
2018-04-27 15:28     ` Jeffrin Thalakkottoor
2018-04-26 21:33 ` John Stultz
2018-04-27 15:27   ` Jeffrin Thalakkottoor

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