Commit-ID: 5d5a08003d3e678372e375d99c65a24e0d33d2f5
Gitweb: http://git.kernel.org/tip/5d5a08003d3e678372e375d99c65a24e0d33d2f5
Author: Kirill Tkhai <tkhai@xxxxxxxxx>
AuthorDate: Sun, 15 Sep 2013 17:29:17 +0400
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Mon, 23 Sep 2013 14:11:11 -0700
rcu: Fix CONFIG_RCU_NOCB_CPU_ALL panic on machines with sparse CPU mask
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@xxxxxxxxx>
CC: Dipankar Sarma <dipankar@xxxxxxxxxx>
[ paulmck: Fix pr_info() issue noted by scripts/checkpatch.pl. ]
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcutree_plugin.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index c684f7a..1855d66 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -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)
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|