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| author | Kirill Tkhai <tkhai@yandex.ru> | 2013-09-15 17:29:17 +0400 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-09-23 14:11:11 -0700 |
| commit | 5d5a08003d3e678372e375d99c65a24e0d33d2f5 (patch) | |
| tree | 3a159a99297f0418b25f1d89933652540c1ed851 /kernel/rcutree_plugin.h | |
| parent | 0d75292467b0c8554d70c751a35af6514202ac28 (diff) | |
| download | lwn-5d5a08003d3e678372e375d99c65a24e0d33d2f5.tar.gz lwn-5d5a08003d3e678372e375d99c65a24e0d33d2f5.zip | |
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@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>
Diffstat (limited to 'kernel/rcutree_plugin.h')
| -rw-r--r-- | kernel/rcutree_plugin.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h index c684f7ab37fa..1855d66bf705 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) |