diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2b8ee90bb644..d377a2166b79 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3623,7 +3623,9 @@ see CONFIG_RAS_CEC help text. rcu_nocbs= [KNL] - The argument is a cpu list, as described above. + The argument is a cpu list, as described above, + except that the string "all" can be used to + specify every CPU on the system. In kernels built with CONFIG_RCU_NOCB_CPU=y, set the specified list of CPUs to be no-callback CPUs. diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index d408661d5fb7..ed4a6dabf31d 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1776,7 +1776,10 @@ static void zero_cpu_stall_ticks(struct rcu_data *rdp) static int __init rcu_nocb_setup(char *str) { alloc_bootmem_cpumask_var(&rcu_nocb_mask); - cpulist_parse(str, rcu_nocb_mask); + if (!strcasecmp(str, "all")) + cpumask_setall(rcu_nocb_mask); + else + cpulist_parse(str, rcu_nocb_mask); return 1; } __setup("rcu_nocbs=", rcu_nocb_setup);