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Commit 5afdbd6e authored by Heiko Carstens's avatar Heiko Carstens Committed by Linus Torvalds
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[PATCH] s390: exploit rcu_needs_cpu() interface 



Exploit rcu_needs_cpu() interface to keep the cpu 'ticking' if necessary.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 986733e0

arch/s390/kernel/time.c

+4 −3
Original line number Original line Diff line number Diff line
@@ -249,18 +249,19 @@ static inline void stop_hz_timer(void) 
	unsigned long flags;

	unsigned long flags;

	unsigned long seq, next;

	unsigned long seq, next;

	__u64 timer, todval;

	__u64 timer, todval;

	int cpu = smp_processor_id();





	if (sysctl_hz_timer != 0)

	if (sysctl_hz_timer != 0)

		return;

		return;





	cpu_set(smp_processor_id(), nohz_cpu_mask);

	cpu_set(cpu, nohz_cpu_mask);





	/*

	/*

	 * Leave the clock comparator set up for the next timer

	 * Leave the clock comparator set up for the next timer

	 * tick if either rcu or a softirq is pending.

	 * tick if either rcu or a softirq is pending.

	 */

	 */

	if (rcu_pending(smp_processor_id()) || local_softirq_pending()) {

	if (rcu_needs_cpu(cpu) || local_softirq_pending()) {

		cpu_clear(smp_processor_id(), nohz_cpu_mask);

		cpu_clear(cpu, nohz_cpu_mask);

		return;

		return;

	}

	}