EXP rcu: Revert expedited GP parallelization cleverness
This commit reverts a series of commits starting with fcc635436501 ("rcu:
Make expedited GPs handle CPU 0 being offline") and its successors, thus
queueing each rcu_node structure's expedited grace-period initialization
work on the first CPU of that rcu_node structure.
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 928fe58..61019a6 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -428,7 +428,6 @@
*/
static void sync_rcu_exp_select_cpus(smp_call_func_t func)
{
- int cpu;
struct rcu_node *rnp;
trace_rcu_exp_grace_period(rcu_state.name, rcu_exp_gp_seq_endval(), TPS("reset"));
@@ -449,15 +448,7 @@
continue;
}
INIT_WORK(&rnp->rew.rew_work, sync_rcu_exp_select_node_cpus);
- preempt_disable();
- cpu = find_next_bit(&rnp->ffmask, BITS_PER_LONG, -1);
- /* If all offline, queue the work on an unbound CPU. */
- if (unlikely(cpu > rnp->grphi - rnp->grplo))
- cpu = WORK_CPU_UNBOUND;
- else
- cpu += rnp->grplo;
- queue_work_on(cpu, rcu_par_gp_wq, &rnp->rew.rew_work);
- preempt_enable();
+ queue_work_on(rnp->grplo, rcu_par_gp_wq, &rnp->rew.rew_work);
rnp->exp_need_flush = true;
}
