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| author | Paul E. McKenney <paul.mckenney@linaro.org> | 2013-02-11 19:23:27 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2013-03-26 16:04:43 +0100 |
| commit | 911af505ef407c2511106c224dd640f882f0f590 (patch) | |
| tree | 00656ef4be8d1195a568951333dd9618265c6435 /kernel/rcutree_plugin.h | |
| parent | rcu: Remove restrictions on no-CBs CPUs (diff) | |
| download | linux-911af505ef407c2511106c224dd640f882f0f590.tar.xz linux-911af505ef407c2511106c224dd640f882f0f590.zip | |
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.h | 14 |
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); |