rcu: Fix CONFIG_RCU_NOCB_CPU_ALL panic on machines with sparse CPU mask (5d5a0800) · Commits · 戴 / test

Some architectures have sparse cpu mask. UltraSparc's cpuinfo for example: CPU0: online CPU2: online So, set only possible CPUs when CONFIG_RCU_NOCB_CPU_ALL is enabled. Also, check that user passes right 'rcu_nocbs=' option. Signed-off-by:

Kirill Tkhai <tkhai@yandex.ru> CC: Dipankar Sarma <dipankar@in.ibm.com> [ paulmck: Fix pr_info() issue noted by scripts/checkpatch.pl. ] Signed-off-by:

Paul E. McKenney <paulmck@linux.vnet.ibm.com>

kernel/rcutree_plugin.h

+6 −1

Original line number	Diff line number	Diff line
		@@ -96,10 +96,15 @@ static void __init rcu_bootup_announce_oddness(void)
		#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */
		#ifdef CONFIG_RCU_NOCB_CPU_ALL
		pr_info("\tOffload RCU callbacks from all CPUs\n");
		cpumask_setall(rcu_nocb_mask);
		cpumask_copy(rcu_nocb_mask, cpu_possible_mask);
		#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */
		#endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */
		if (have_rcu_nocb_mask) {
		if (!cpumask_subset(rcu_nocb_mask, cpu_possible_mask)) {
		pr_info("\tNote: kernel parameter 'rcu_nocbs=' contains nonexistent CPUs.\n");
		cpumask_and(rcu_nocb_mask, cpu_possible_mask,
		rcu_nocb_mask);
		}
		cpulist_scnprintf(nocb_buf, sizeof(nocb_buf), rcu_nocb_mask);
		pr_info("\tOffload RCU callbacks from CPUs: %s.\n", nocb_buf);
		if (rcu_nocb_poll)

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