From a488985851cf2facd2227bd982cc2c251df56268 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 3 Dec 2012 08:16:28 -0800 Subject: 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 Signed-off-by: Paul E. McKenney Tested-by: Dietmar Eggemann --- Documentation/kernel-parameters.txt | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4609e81dbc37..a17ba16c8fc8 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2461,9 +2461,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted. In kernels built with CONFIG_RCU_NOCB_CPU=y, set the specified list of CPUs to be no-callback CPUs. Invocation of these CPUs' RCU callbacks will - be offloaded to "rcuoN" kthreads created for - that purpose. This reduces OS jitter on the + be offloaded to "rcuox/N" kthreads created for + that purpose, where "x" is "b" for RCU-bh, "p" + for RCU-preempt, and "s" for RCU-sched, and "N" + is the CPU number. This reduces OS jitter on the offloaded CPUs, which can be useful for HPC and + real-time workloads. It can also improve energy efficiency for asymmetric multiprocessors. -- cgit v1.2.3