[GIT PULL clocksource] Clocksource watchdog commits for v5.17

[Paul E. McKenney]

Hello, Thomas,

This pull request contains a pair of changes, both courtesy of Waiman
Long:

1.	Avoids accidental unstable marking of clocksources by rejecting
	clocksource measurements where the source of the skew is the delay
	reading reference clocksource itself.  This change avoids many
	of the current false positives caused by epic cache-thrashing
	workloads.

	https://lore.kernel.org/lkml/20211118191439.1000012-2-longman@xxxxxxxxxx/

2.	Reduces the default clocksource_watchdog() retries to 2, thus
	offsetting the increased overhead due to #1 above rereading the
	reference clocksource.

	https://lore.kernel.org/lkml/20211118191439.1000012-3-longman@xxxxxxxxxx/

These have been subjected to the kbuild test robot and -next testing,
and are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git clocksource

for you to fetch changes up to 1a5620671a1b6fd9cc08761677d050f1702f910c:

  clocksource: Reduce the default clocksource_watchdog() retries to 2 (2021-11-30 17:22:29 -0800)

----------------------------------------------------------------
Waiman Long (2):
      clocksource: Avoid accidental unstable marking of clocksources
      clocksource: Reduce the default clocksource_watchdog() retries to 2

 Documentation/admin-guide/kernel-parameters.txt |  4 +-
 kernel/time/clocksource.c                       | 52 ++++++++++++++++++++-----
 2 files changed, 44 insertions(+), 12 deletions(-)