rcu: Distinguish "rcuo" kthreads by RCU flavor

Currently, the per-no-CBs-CPU kthreads are named "rcuo" followed by
the CPU number, for example, "rcuo".  This is problematic given that
there are either two or three RCU flavors, each of which gets a per-CPU
kthread with exactly the same name.  This commit therefore introduces
a one-letter abbreviation for each RCU flavor, namely 'b' for RCU-bh,
'p' for RCU-preempt, and 's' for RCU-sched.  This abbreviation is used
to distinguish the "rcuo" kthreads, for example, for CPU 0 we would have
"rcuob/0", "rcuop/0", and "rcuos/0".

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/init/Kconfig b/init/Kconfig
index 307499704580..717584064a7e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -666,12 +666,13 @@ config RCU_NOCB_CPU
 
           This option offloads callback invocation from the set of
           CPUs specified at boot time by the rcu_nocbs parameter.
-          For each such CPU, a kthread ("rcuoN") will be created to
-          invoke callbacks, where the "N" is the CPU being offloaded.
-          Nothing prevents this kthread from running on the specified
-          CPUs, but (1) the kthreads may be preempted between each
-          callback, and (2) affinity or cgroups can be used to force
-          the kthreads to run on whatever set of CPUs is desired.
+          For each such CPU, a kthread ("rcuox/N") will be created to
+          invoke callbacks, where the "N" is the CPU being offloaded,
+          and where the "x" is "b" for RCU-bh, "p" for RCU-preempt, and
+          "s" for RCU-sched.  Nothing prevents this kthread from running
+          on the specified CPUs, but (1) the kthreads may be preempted
+          between each callback, and (2) affinity or cgroups can be used
+          to force the kthreads to run on whatever set of CPUs is desired.
 
           Say Y here if you want to help to debug reduced OS jitter.
           Say N here if you are unsure.