From: Petr Vorel <pvorel@suse.cz>
To: Cyril Hrubis <chrubis@suse.cz>
Cc: Claude <noreply@anthropic.com>, Linux Test Project <ltp@lists.linux.it>
Subject: Re: [LTP] [PATCH v2] clock_settime: Detect external clock adjustments via CLOCK_MONOTONIC
Date: Wed, 29 Apr 2026 09:50:29 +0200 [thread overview]
Message-ID: <20260429075029.GA968839@pevik> (raw)
In-Reply-To: <acvWwBNhJ5b8A7r2@rei.lan>
> Hi!
> > These tests manipulate CLOCK_REALTIME to verify timer and
> > clock_nanosleep behavior, but NTP or VM time sync can also adjust
> > CLOCK_REALTIME during the test, causing timers to fire at wrong times
> > and producing spurious failures.
> > Use CLOCK_MONOTONIC as a sideband check to detect external interference.
> > If the monotonic elapsed time is anomalous, report UNTESTED instead of
> > a false FAIL. Guard the checks with _POSIX_MONOTONIC_CLOCK since
> > CLOCK_MONOTONIC is optional in POSIX.1-2001.
> Maybe we can retry a few times before we give up and report untested?
+1.
Kind regards,
Petr
--
Mailing list info: https://lists.linux.it/listinfo/ltp
prev parent reply other threads:[~2026-04-29 7:51 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-31 12:37 [LTP] [PATCH v2] clock_settime: Detect external clock adjustments via CLOCK_MONOTONIC Andrea Cervesato
2026-03-31 14:14 ` Cyril Hrubis
2026-04-29 7:50 ` Petr Vorel [this message]
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=20260429075029.GA968839@pevik \
--to=pvorel@suse.cz \
--cc=chrubis@suse.cz \
--cc=ltp@lists.linux.it \
--cc=noreply@anthropic.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox