From: Miroslav Lichvar <mlichvar@redhat.com>
To: John Stultz <john.stultz@linaro.org>
Cc: lkml <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@kernel.org>,
Richard Cochran <richardcochran@gmail.com>,
Prarit Bhargava <prarit@redhat.com>,
Stephen Boyd <stephen.boyd@linaro.org>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Will Deacon <will.deacon@arm.com>,
Daniel Mentz <danielmentz@google.com>,
"stable #4 . 8+" <stable@vger.kernel.org>
Subject: Re: [PATCH 2/3 v3] time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting
Date: Tue, 13 Jun 2017 12:30:26 +0200 [thread overview]
Message-ID: <20170613103026.GF4221@localhost> (raw)
In-Reply-To: <1496965462-20003-3-git-send-email-john.stultz@linaro.org>
On Thu, Jun 08, 2017 at 04:44:21PM -0700, John Stultz wrote:
> Due to how the MONOTONIC_RAW accumulation logic was handled,
> there is the potential for a 1ns discontinuity when we do
> accumulations. This small discontinuity has for the most part
> gone un-noticed, but since ARM64 enabled CLOCK_MONOTONIC_RAW
> in their vDSO clock_gettime implementation, we've seen failures
> with the inconsistency-check test in kselftest.
>
> This patch addresses the issue by using the same sub-ns
> accumulation handling that CLOCK_MONOTONIC uses, which avoids
> the issue for in-kernel users.
The patch looks good to me and in testing on x86_64 I didn't see any
issues with the CLOCK_MONOTONIC_RAW clock.
Thanks,
--
Miroslav Lichvar
next prev parent reply other threads:[~2017-06-13 10:30 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-08 23:44 [PATCH 0/3 v3] Fixes for two recently found timekeeping bugs John Stultz
2017-06-08 23:44 ` [PATCH 1/3 v3] time: Fix clock->read(clock) race around clocksource changes John Stultz
2017-06-20 8:46 ` [tip:timers/urgent] " tip-bot for John Stultz
2017-06-08 23:44 ` [PATCH 2/3 v3] time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting John Stultz
2017-06-13 10:30 ` Miroslav Lichvar [this message]
2017-06-20 8:46 ` [tip:timers/urgent] " tip-bot for John Stultz
2017-06-08 23:44 ` [PATCH 3/3 v3] arm64: vdso: Fix nsec handling for CLOCK_MONOTONIC_RAW John Stultz
2017-06-20 8:47 ` [tip:timers/urgent] arm64/vdso: " tip-bot for Will Deacon
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=20170613103026.GF4221@localhost \
--to=mlichvar@redhat.com \
--cc=danielmentz@google.com \
--cc=john.stultz@linaro.org \
--cc=kevin.brodsky@arm.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=prarit@redhat.com \
--cc=richardcochran@gmail.com \
--cc=stable@vger.kernel.org \
--cc=stephen.boyd@linaro.org \
--cc=tglx@linutronix.de \
--cc=will.deacon@arm.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.