From f092eb34b33043152bfb8a4ca01db9a06728261d Mon Sep 17 00:00:00 2001
From: "Paul E. McKenney" <paulmck@kernel.org>
Date: Tue, 13 Dec 2022 13:57:28 -0800
Subject: [PATCH] clocksource: Improve read-back-delay message
Git-commit: f092eb34b33043152bfb8a4ca01db9a06728261d
Patch-mainline: v6.3-rc1
References: bsc#1215885 bsc#1217217
When cs_watchdog_read() is unable to get a qualifying clocksource read
within the limit set by max_cswd_read_retries, it prints a message
and marks the clocksource under test as unstable. But that message is
unclear to anyone unfamiliar with the code:
clocksource: timekeeping watchdog on CPU13: wd-tsc-wd read-back delay 1000614ns, attempt 3, marking unstable
Therefore, add some context so that the message appears as follows:
clocksource: timekeeping watchdog on CPU13: wd-tsc-wd excessive read-back delay of 1000614ns vs. limit of 125000ns, wd-wd read-back delay only 27ns, attempt 3, marking tsc unstable
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: John Stultz <jstultz@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: Feng Tang <feng.tang@intel.com>
Signed-off-by: Jiri Wiesner <jwiesner@suse.de>
---
kernel/time/clocksource.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index a3d19f6660ac..b59914953809 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -260,8 +260,8 @@ static enum wd_read_status cs_watchdog_read(struct clocksource *cs, u64 *csnow,
goto skip_test;
}
- pr_warn("timekeeping watchdog on CPU%d: wd-%s-wd read-back delay of %lldns, attempt %d, marking unstable\n",
- smp_processor_id(), cs->name, wd_delay, nretries);
+ pr_warn("timekeeping watchdog on CPU%d: wd-%s-wd excessive read-back delay of %lldns vs. limit of %ldns, wd-wd read-back delay only %lldns, attempt %d, marking %s unstable\n",
+ smp_processor_id(), cs->name, wd_delay, WATCHDOG_MAX_SKEW, wd_seq_delay, nretries, cs->name);
return WD_READ_UNSTABLE;
skip_test:
--
2.35.3