[tip: timers/clocksource] clocksource: Fix comments on WATCHDOG_THRESHOLD & WATCHDOG_MAX_SKEW

[tip-bot2 for Paul E. McKenney]

The following commit has been merged into the timers/clocksource branch of tip:

Commit-ID:     f33a5d4bd9c2e545857b2cf7481eb721bcab867c
Gitweb:        https://git.kernel.org/tip/f33a5d4bd9c2e545857b2cf7481eb721bcab867c
Author:        Paul E. McKenney <paulmck@xxxxxxxxxx>
AuthorDate:    Fri, 02 Aug 2024 08:46:16 -07:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Fri, 02 Aug 2024 18:37:13 +02:00

clocksource: Fix comments on WATCHDOG_THRESHOLD & WATCHDOG_MAX_SKEW

The WATCHDOG_THRESHOLD macro is no longer used to supply a default value
for ->uncertainty_margin, but WATCHDOG_MAX_SKEW now is.

Therefore, update the comments to reflect this change.

Reported-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Link: https://lore.kernel.org/all/20240802154618.4149953-3-paulmck@xxxxxxxxxx

---
 kernel/time/clocksource.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 581cdbb..ee0ad5e 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -113,7 +113,6 @@ static u64 suspend_start;
 
 /*
  * Threshold: 0.0312s, when doubled: 0.0625s.
- * Also a default for cs->uncertainty_margin when registering clocks.
  */
 #define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 5)
 
@@ -139,6 +138,13 @@ static u64 suspend_start;
 #define MAX_SKEW_USEC	(125 * WATCHDOG_INTERVAL / HZ)
 #endif
 
+/*
+ * Default for maximum permissible skew when cs->uncertainty_margin is
+ * not specified, and the lower bound even when cs->uncertainty_margin
+ * is specified.  This is also the default that is used when registering
+ * clocks with unspecifed cs->uncertainty_margin, so this macro is used
+ * even in CONFIG_CLOCKSOURCE_WATCHDOG=n kernels.
+ */
 #define WATCHDOG_MAX_SKEW (MAX_SKEW_USEC * NSEC_PER_USEC)
 
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG