LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: tip-bot for Peter Zijlstra <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: peterz@infradead.org, rafael.j.wysocki@intel.com, hpa@zytor.com,
	linux-kernel@vger.kernel.org, mingo@kernel.org,
	tglx@linutronix.de
Subject: [tip:timers/urgent] clocksource: Consistent de-rate when marking unstable
Date: Wed, 2 May 2018 07:14:52 -0700	[thread overview]
Message-ID: <tip-cd2af07d823e5287cd6c91d54337348c2a873462@git.kernel.org> (raw)
In-Reply-To: <20180430100344.594904898@infradead.org>

Commit-ID:  cd2af07d823e5287cd6c91d54337348c2a873462
Gitweb:     https://git.kernel.org/tip/cd2af07d823e5287cd6c91d54337348c2a873462
Author:     Peter Zijlstra <peterz@infradead.org>
AuthorDate: Mon, 30 Apr 2018 12:00:13 +0200
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Wed, 2 May 2018 16:10:41 +0200

clocksource: Consistent de-rate when marking unstable

When a registered clocksource gets marked unstable the watchdog_kthread
will de-rate and re-select the clocksource. Ensure it also de-rates
when getting called on an unregistered clocksource.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: len.brown@intel.com
Cc: rjw@rjwysocki.net
Cc: diego.viola@gmail.com
Cc: rui.zhang@intel.com
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180430100344.594904898@infradead.org

---
 kernel/time/clocksource.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 935f39eb8aac..605656df16c4 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -152,12 +152,19 @@ static void __clocksource_unstable(struct clocksource *cs)
 	cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
 	cs->flags |= CLOCK_SOURCE_UNSTABLE;
 
-	if (list_empty(&cs->list))
+	/*
+	 * If the clocksource is registered clocksource_watchdog_kthread() will
+	 * re-rate and re-select.
+	 */
+	if (list_empty(&cs->list)) {
+		cs->rating = 0;
 		return;
+	}
 
 	if (cs->mark_unstable)
 		cs->mark_unstable(cs);
 
+	/* kick clocksource_watchdog_kthread() */
 	if (finished_booting)
 		schedule_work(&watchdog_work);
 }

  reply	other threads:[~2018-05-02 14:15 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-30 10:00 [PATCH v2 0/7] Various tsc/clocksource fixes Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 1/7] x86,tsc: Always unregister clocksource_tsc_early Peter Zijlstra
2018-05-02 14:12   ` [tip:timers/urgent] x86/tsc: " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 2/7] clocksource: Allow clocksource_mark_unstable() on unregisered clocksources Peter Zijlstra
2018-05-02 13:35   ` Thomas Gleixner
2018-05-02 13:53     ` Peter Zijlstra
2018-05-02 14:13       ` [tip:timers/urgent] clocksource: Allow clocksource_mark_unstable() on unregistered clocksources tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 3/7] clocksource: Initialize cs->wd_list Peter Zijlstra
2018-05-02 13:37   ` Thomas Gleixner
2018-05-02 13:55     ` Peter Zijlstra
2018-05-02 14:13   ` [tip:timers/urgent] " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 4/7] x86,tsc: Fix mark_tsc_unstable() Peter Zijlstra
2018-05-02 14:14   ` [tip:timers/urgent] x86/tsc: " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 5/7] clocksource: Consistent de-rate when marking unstable Peter Zijlstra
2018-05-02 14:14   ` tip-bot for Peter Zijlstra [this message]
2018-04-30 10:00 ` [PATCH v2 6/7] clocksource: Rework stale comment Peter Zijlstra
2018-05-02 14:15   ` [tip:timers/urgent] " tip-bot for Peter Zijlstra
2018-04-30 10:00 ` [PATCH v2 7/7] clocksource: Remove kthread Peter Zijlstra
2018-05-02 14:42   ` [tip:timers/core] " tip-bot for Peter Zijlstra
2018-05-01  9:12 ` [PATCH v2 0/7] Various tsc/clocksource fixes Rafael J. Wysocki

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=tip-cd2af07d823e5287cd6c91d54337348c2a873462@git.kernel.org \
    --to=tipbot@zytor.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=peterz@infradead.org \
    --cc=rafael.j.wysocki@intel.com \
    --cc=tglx@linutronix.de \
    --subject='Re: [tip:timers/urgent] clocksource: Consistent de-rate when marking unstable' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).