linux-kernel - [tip:timers/urgent] Revert "tick: Prefer a lower rating device only if it's CPU local device"

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Message-ID: <tip-5b5ccbc2b041f98f26b984e013d303b7f9e6fb8e@git.kernel.org>
Date:   Tue, 10 Jul 2018 13:15:56 -0700
From:   tip-bot for Sudeep Holla <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     marc.zyngier@....com, mingo@...nel.org, sudeep.holla@....com,
        martin.blumenstingl@...glemail.com, linux-kernel@...r.kernel.org,
        khilman@...libre.com, tglx@...utronix.de, hpa@...or.com
Subject: [tip:timers/urgent] Revert "tick: Prefer a lower rating device only
 if it's CPU local device"

Commit-ID:  5b5ccbc2b041f98f26b984e013d303b7f9e6fb8e
Gitweb:     https://git.kernel.org/tip/5b5ccbc2b041f98f26b984e013d303b7f9e6fb8e
Author:     Sudeep Holla <sudeep.holla@....com>
AuthorDate: Mon, 9 Jul 2018 16:45:35 +0100
Committer:  Thomas Gleixner <tglx@...utronix.de>
CommitDate: Tue, 10 Jul 2018 22:12:47 +0200

Revert "tick: Prefer a lower rating device only if it's CPU local device"

This reverts commit 1332a90558013ae4242e3dd7934bdcdeafb06c0d.

The original issue was not because of incorrect checking of cpumask for
both new and old tick device. It was incorrectly analysed was due to the
misunderstanding of the comment and misinterpretation of the return value
from tick_check_preferred. The main issue is with the clockevent driver
that sets the cpumask to cpu_all_mask instead of cpu_possible_mask.

Signed-off-by: Sudeep Holla <sudeep.holla@....com>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Tested-by: Kevin Hilman <khilman@...libre.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@...glemail.com>
Cc: linux-arm-kernel@...ts.infradead.org
Cc: Marc Zyngier <marc.zyngier@....com>
Link: https://lkml.kernel.org/r/1531151136-18297-1-git-send-email-sudeep.holla@arm.com

---
 kernel/time/tick-common.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index b7005dd21ec1..14de3727b18e 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -277,8 +277,7 @@ static bool tick_check_preferred(struct clock_event_device *curdev,
 	 */
 	return !curdev ||
 		newdev->rating > curdev->rating ||
-	       (!cpumask_equal(curdev->cpumask, newdev->cpumask) &&
-	        !tick_check_percpu(curdev, newdev, smp_processor_id()));
+	       !cpumask_equal(curdev->cpumask, newdev->cpumask);
 }
 
 /*