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clocksource/wdtest: Print time values for short udelay(1)

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When a pair of clocksource reads separated by a udelay(1) claim less than a
full microsecond of elapsed time, print the measured delay as part of the
splat.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/717a2ddf-a80f-490b-aa3a-4e4b74fa56ca@paulmck-laptop
This commit is contained in:
Paul E. McKenney 2024-12-12 10:56:20 -08:00 committed by Thomas Gleixner
parent 9f38e83a88
commit 776b194116
1 changed files with 2 additions and 1 deletions
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3
kernel/time/clocksource-wdtest.c
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@ -137,7 +137,8 @@ static int wdtest_func(void *arg)
udelay(1);
j2 = clocksource_wdtest_ktime.read(&clocksource_wdtest_ktime);
pr_info("--- tsc-like times: %lu - %lu = %lu.\n", j2, j1, j2 - j1);
WARN_ON_ONCE(time_before(j2, j1 + NSEC_PER_USEC));
WARN_ONCE(time_before(j2, j1 + NSEC_PER_USEC),
"Expected at least 1000ns, got %lu.\n", j2 - j1);
/* Verify tsc-like stability with various numbers of errors injected. */
max_retries = clocksource_get_max_watchdog_retry();