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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-08-15 19:00:31 -0700
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-10-07 16:02:50 -0700
commitdcdb8807ba0f5127d4dc67daeeb154edf50a93d1 (patch)
treee303f8279f7a4e0f13d72f092fb6d52091b88320 /kernel/rcu/tree_plugin.h
parent66fe6cbee44e3f78d05882195a6a38e30b97b936 (diff)
downloadlinux-sh-dcdb8807ba0f5127d4dc67daeeb154edf50a93d1.tar.gz
rcu: Consolidate expedited CPU selection
Now that sync_sched_exp_select_cpus() and sync_rcu_exp_select_cpus() are identical aside from the the argument to smp_call_function_single(), this commit consolidates them with a functional argument. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree_plugin.h')
-rw-r--r--kernel/rcu/tree_plugin.h61
1 files changed, 1 insertions, 60 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 7880202f1e38..6cbfbfc58656 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -708,65 +708,6 @@ static void sync_rcu_exp_handler(void *info)
rcu_report_exp_rdp(rsp, rdp, true);
}
-/*
- * Select the nodes that the upcoming expedited grace period needs
- * to wait for.
- */
-static void sync_rcu_exp_select_cpus(struct rcu_state *rsp)
-{
- int cpu;
- unsigned long flags;
- unsigned long mask;
- unsigned long mask_ofl_test;
- unsigned long mask_ofl_ipi;
- int ret;
- struct rcu_node *rnp;
-
- sync_exp_reset_tree(rsp);
- rcu_for_each_leaf_node(rsp, rnp) {
- raw_spin_lock_irqsave(&rnp->lock, flags);
- smp_mb__after_unlock_lock();
-
- /* Each pass checks a CPU for identity, offline, and idle. */
- mask_ofl_test = 0;
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++) {
- struct rcu_data *rdp = per_cpu_ptr(rsp->rda, cpu);
- struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
-
- if (raw_smp_processor_id() == cpu ||
- cpu_is_offline(cpu) ||
- !(atomic_add_return(0, &rdtp->dynticks) & 0x1))
- mask_ofl_test |= rdp->grpmask;
- }
- mask_ofl_ipi = rnp->expmask & ~mask_ofl_test;
-
- /*
- * Need to wait for any blocked tasks as well. Note that
- * additional blocking tasks will also block the expedited
- * GP until such time as the ->expmask bits are cleared.
- */
- if (rcu_preempt_has_tasks(rnp))
- rnp->exp_tasks = rnp->blkd_tasks.next;
- raw_spin_unlock_irqrestore(&rnp->lock, flags);
-
- /* IPI the remaining CPUs for expedited quiescent state. */
- mask = 1;
- for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask <<= 1) {
- if (!(mask_ofl_ipi & mask))
- continue;
- ret = smp_call_function_single(cpu,
- sync_rcu_exp_handler,
- rsp, 0);
- if (!ret)
- mask_ofl_ipi &= ~mask;
- }
- /* Report quiescent states for those that went offline. */
- mask_ofl_test |= mask_ofl_ipi;
- if (mask_ofl_test)
- rcu_report_exp_cpu_mult(rsp, rnp, mask_ofl_test, false);
- }
-}
-
/**
* synchronize_rcu_expedited - Brute-force RCU grace period
*
@@ -795,7 +736,7 @@ void synchronize_rcu_expedited(void)
rcu_exp_gp_seq_start(rsp);
/* Initialize the rcu_node tree in preparation for the wait. */
- sync_rcu_exp_select_cpus(rsp);
+ sync_rcu_exp_select_cpus(rsp, sync_rcu_exp_handler);
/* Wait for snapshotted ->blkd_tasks lists to drain. */
rnp = rcu_get_root(rsp);