Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH tip/core/rcu 11/11] rcu: Fix CONFIG_RCU_NOCB_CPU_ALL panic on machines with sparse CPU mask | Date | Tue, 24 Sep 2013 18:29:21 -0700 |
| |
From: Kirill Tkhai <tkhai@yandex.ru>
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 | 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) -- 1.8.1.5
| |