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
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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]
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