From: Joerg Vehlow <lkml@jv-coder.de>
To: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Ingo Molnar <mingo@kernel.org>,
John Stultz <john.stultz@linaro.org>
Subject: Re: [4.14] Failing selftest timer/adjtick
Date: Mon, 1 Mar 2021 08:04:18 +0100 [thread overview]
Message-ID: <c0a32d60-073e-3faa-6529-97b1a8c7fdaf@jv-coder.de> (raw)
In-Reply-To: <20210211105944.GG1903164@localhost>
Hi Mi
On 2/11/2021 11:59 AM, Miroslav Lichvar wrote:
> I don't think it is specific to arm or that it is a regression. I
> think the virtual machine just happens to be too idle for the test.
> There may be unrelated changes, maybe in the kernel, qemu, or
> applications, that caused the rate of the clock updates to decrease so
> much that the instability now triggers the failure in the test. The
> issue with the clock was there since NO_HZ was introduced, but it
> becomes more severe as the activity of the kernel decreases.
Thanks for the hint towards NO_HZ. Running the tests with some
background load makes them pass reliably.
Jörg
prev parent reply other threads:[~2021-03-01 7:06 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-10 12:43 [4.14] Failing selftest timer/adjtick Joerg Vehlow
2021-02-10 13:00 ` Greg KH
2021-02-10 13:07 ` Joerg Vehlow
2021-02-10 13:19 ` Miroslav Lichvar
2021-02-10 18:59 ` Naresh Kamboju
2021-02-11 10:34 ` Joerg Vehlow
2021-02-11 10:33 ` Joerg Vehlow
2021-02-11 10:45 ` Greg KH
2021-02-11 10:59 ` Miroslav Lichvar
2021-02-18 7:05 ` Joerg Vehlow
2021-03-01 7:04 ` Joerg Vehlow [this message]
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