Messages in this thread | | | Date | Wed, 23 Jul 2014 06:42:13 -0700 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH 15/16] rcu: Check for a nocb cpu before trying to spawn nocb threads |
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On Wed, Jul 23, 2014 at 09:14:51AM -0400, Pranith Kumar wrote: > On Wed, Jul 23, 2014 at 8:28 AM, Paul E. McKenney > <paulmck@linux.vnet.ibm.com> wrote: > > On Wed, Jul 23, 2014 at 01:09:52AM -0400, Pranith Kumar wrote: > >> This commit tries to spawn nocb kthreads only when the CPU is marked as a nocb > >> cpu. This is a minor optimization. > >> > >> Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> > > > > This only happens once at boot time, so I am happier with the single check > > at the bottom. So sorry, but no. > > Actually this happens whenever a CPU is coming online, but yes, it is > a minor optimization for hotplug.
Fair point, but still.
Thanx, Paul
> >> --- > >> kernel/rcu/tree_plugin.h | 3 ++- > >> 1 file changed, 2 insertions(+), 1 deletion(-) > >> > >> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h > >> index 541c776..8abff0a 100644 > >> --- a/kernel/rcu/tree_plugin.h > >> +++ b/kernel/rcu/tree_plugin.h > >> @@ -1490,7 +1490,8 @@ static void rcu_prepare_kthreads(int cpu) > >> return; > >> > >> rcu_spawn_one_boost_kthread(rcu_state_p, rnp); > >> - rcu_spawn_all_nocb_kthreads(cpu); > >> + if (rcu_is_nocb_cpu(cpu)) > >> + rcu_spawn_all_nocb_kthreads(cpu); > >> } > >> > >> #else /* #ifdef CONFIG_RCU_BOOST */ > >> -- > >> 2.0.0.rc2 > >> > > > > > > -- > Pranith >
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