From: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri, 4 Sep 2015 22:45:09 +0000 (-0700)
Subject: watchdog: simplify housekeeping affinity with the appropriate mask
X-Git-Tag: firefly_0821_release~176^2~1136^2~64
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=314b08ff5205420d956d14657e16d92c460a6f21;p=firefly-linux-kernel-4.4.55.git

watchdog: simplify housekeeping affinity with the appropriate mask

housekeeping_mask gathers all the CPUs that aren't part of the nohz_full
set.  This is exactly what we want the watchdog to be affine to without
the need to use complicated cpumask operations.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Chris Metcalf <cmetcalf@ezchip.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index e5bb86fb0ea5..d18330fa4776 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -929,10 +929,8 @@ void __init lockup_detector_init(void)
 
 #ifdef CONFIG_NO_HZ_FULL
 	if (tick_nohz_full_enabled()) {
-		if (!cpumask_empty(tick_nohz_full_mask))
-			pr_info("Disabling watchdog on nohz_full cores by default\n");
-		cpumask_andnot(&watchdog_cpumask, cpu_possible_mask,
-			       tick_nohz_full_mask);
+		pr_info("Disabling watchdog on nohz_full cores by default\n");
+		cpumask_copy(&watchdog_cpumask, housekeeping_mask);
 	} else
 		cpumask_copy(&watchdog_cpumask, cpu_possible_mask);
 #else