On Thu, 2018-05-17 at 07:03 -0700, Paul E. McKenney wrote: > On Tue, May 15, 2018 at 06:30:26AM +0200, Mike Galbraith wrote: > > > > Something like so perhaps? Mike, can you play around with that? Could > > > burn your granny and eat your cookies. > > > > Did this get queued anywhere? > > I have not queued it, but given Peter's Signed-off-by and your Tested-by > I would be happy to do so.
Here's the later. Tested-by: Mike Galbraith <efa...@gmx.de> > > > diff --git a/arch/x86/kernel/cpu/mtrr/main.c > > > b/arch/x86/kernel/cpu/mtrr/main.c > > > index 7468de429087..07360523c3ce 100644 > > > --- a/arch/x86/kernel/cpu/mtrr/main.c > > > +++ b/arch/x86/kernel/cpu/mtrr/main.c > > > @@ -793,6 +793,9 @@ void mtrr_ap_init(void) > > > > > > if (!use_intel() || mtrr_aps_delayed_init) > > > return; > > > + > > > + rcu_cpu_starting(smp_processor_id()); > > > + > > > /* > > > * Ideally we should hold mtrr_mutex here to avoid mtrr entries > > > * changed, but this routine will be called in cpu boot time, > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > > index 2a734692a581..4dab46950fdb 100644 > > > --- a/kernel/rcu/tree.c > > > +++ b/kernel/rcu/tree.c > > > @@ -3775,6 +3775,8 @@ int rcutree_dead_cpu(unsigned int cpu) > > > return 0; > > > } > > > > > > +static DEFINE_PER_CPU(int, rcu_cpu_started); > > > + > > > /* > > > * Mark the specified CPU as being online so that subsequent grace > > > periods > > > * (both expedited and normal) will wait on it. Note that this means > > > that > > > @@ -3796,6 +3798,11 @@ void rcu_cpu_starting(unsigned int cpu) > > > struct rcu_node *rnp; > > > struct rcu_state *rsp; > > > > > > + if (per_cpu(rcu_cpu_started, cpu)) > > > + return; > > > + > > > + per_cpu(rcu_cpu_started, cpu) = 1; > > > + > > > for_each_rcu_flavor(rsp) { > > > rdp = per_cpu_ptr(rsp->rda, cpu); > > > rnp = rdp->mynode; > > > @@ -3852,6 +3859,8 @@ void rcu_report_dead(unsigned int cpu) > > > preempt_enable(); > > > for_each_rcu_flavor(rsp) > > > rcu_cleanup_dying_idle_cpu(cpu, rsp); > > > + > > > + per_cpu(rcu_cpu_started, cpu) = 0; > > > } > > > > > > /* Migrate the dead CPU's callbacks to the current CPU. */ > > >