Commit 776b1941 authored by Paul E. McKenney's avatar Paul E. McKenney Committed by Thomas Gleixner
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clocksource/wdtest: Print time values for short udelay(1) 



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: default avatarPaul E. McKenney <paulmck@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/717a2ddf-a80f-490b-aa3a-4e4b74fa56ca@paulmck-laptop
parent 9f38e83a

kernel/time/clocksource-wdtest.c

+2 −1
Original line number Diff line number Diff line
@@ -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();