rcu: Create rcuo kthreads only for onlined CPUs
authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Fri, 11 Jul 2014 18:30:24 +0000 (11:30 -0700)
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Tue, 16 Sep 2014 17:08:02 +0000 (10:08 -0700)
commit35ce7f29a44a888c45c0a9f202f69e10613c5306
tree71d72916c0582574a4317aaabd4f24291547326b
parent9386c0b75dda05f535a10ea1abf1817fe292c81c
rcu: Create rcuo kthreads only for onlined CPUs

RCU currently uses for_each_possible_cpu() to spawn rcuo kthreads,
which can result in more rcuo kthreads than one would expect, for
example, derRichard reported 64 CPUs worth of rcuo kthreads on an
8-CPU image.  This commit therefore creates rcuo kthreads only for
those CPUs that actually come online.

This was reported by derRichard on the OFTC IRC network.

Reported-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com>
kernel/rcu/tree.c
kernel/rcu/tree.h
kernel/rcu/tree_plugin.h