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Subject[PATCH 03/12] housekeeping: Provide a dynamic off-case to housekeeping_any_cpu()
Date
housekeeping_any_cpu() doesn't handle correctly the case where
CONFIG_NO_HZ_FULL=y and no CPU is in nohz_full mode. So far no caller
needs this but let's prepare to avoid any future surprise.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <kernellwp@gmail.com>
---
include/linux/sched/isolation.h | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h
index b7cfbc4..040df04 100644
--- a/include/linux/sched/isolation.h
+++ b/include/linux/sched/isolation.h
@@ -7,24 +7,19 @@

#ifdef CONFIG_NO_HZ_FULL
extern cpumask_var_t housekeeping_mask;
-
-static inline int housekeeping_any_cpu(void)
-{
- return cpumask_any_and(housekeeping_mask, cpu_online_mask);
-}
-
extern void __init housekeeping_init(void);
-
#else
-
-static inline int housekeeping_any_cpu(void)
-{
- return smp_processor_id();
-}
-
static inline void housekeeping_init(void) { }
#endif /* CONFIG_NO_HZ_FULL */

+static inline int housekeeping_any_cpu(void)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ if (tick_nohz_full_enabled())
+ return cpumask_any_and(housekeeping_mask, cpu_online_mask);
+#endif
+ return smp_processor_id();
+}

static inline const struct cpumask *housekeeping_cpumask(void)
{
--
2.7.4
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