summaryrefslogtreecommitdiff
path: root/kernel/rcutree_plugin.h
diff options
context:
space:
mode:
authorPaul E. McKenney <paul.mckenney@linaro.org>2013-02-11 10:23:27 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2013-03-26 08:04:43 -0700
commit911af505ef407c2511106c224dd640f882f0f590 (patch)
tree00656ef4be8d1195a568951333dd9618265c6435 /kernel/rcutree_plugin.h
parent34ed62461ae4970695974afb9a60ac3df0086830 (diff)
rcu: Provide compile-time control for no-CBs CPUs
Currently, the only way to specify no-CBs CPUs is via the rcu_nocbs kernel command-line parameter. This is inconvenient in some cases, particularly for randconfig testing, so this commit adds a new set of kernel configuration parameters. CONFIG_RCU_NOCB_CPU_NONE (the default) retains the old behavior, CONFIG_RCU_NOCB_CPU_ZERO offloads callback processing from CPU 0 (along with any other CPUs specified by the rcu_nocbs boot-time parameter), and CONFIG_RCU_NOCB_CPU_ALL offloads callback processing from all CPUs. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutree_plugin.h')
-rw-r--r--kernel/rcutree_plugin.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 44f958a88b21..3e33aefce0ea 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -85,6 +85,20 @@ static void __init rcu_bootup_announce_oddness(void)
if (nr_cpu_ids != NR_CPUS)
printk(KERN_INFO "\tRCU restricting CPUs from NR_CPUS=%d to nr_cpu_ids=%d.\n", NR_CPUS, nr_cpu_ids);
#ifdef CONFIG_RCU_NOCB_CPU
+#ifndef CONFIG_RCU_NOCB_CPU_NONE
+ if (!have_rcu_nocb_mask) {
+ alloc_bootmem_cpumask_var(&rcu_nocb_mask);
+ have_rcu_nocb_mask = true;
+ }
+#ifdef CONFIG_RCU_NOCB_CPU_ZERO
+ pr_info("\tExperimental no-CBs CPU 0\n");
+ cpumask_set_cpu(0, rcu_nocb_mask);
+#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ZERO */
+#ifdef CONFIG_RCU_NOCB_CPU_ALL
+ pr_info("\tExperimental no-CBs for all CPUs\n");
+ cpumask_setall(rcu_nocb_mask);
+#endif /* #ifdef CONFIG_RCU_NOCB_CPU_ALL */
+#endif /* #ifndef CONFIG_RCU_NOCB_CPU_NONE */
if (have_rcu_nocb_mask) {
cpulist_scnprintf(nocb_buf, sizeof(nocb_buf), rcu_nocb_mask);
pr_info("\tExperimental no-CBs CPUs: %s.\n", nocb_buf);