Commit-ID: dcdb8807ba0f5127d4dc67daeeb154edf50a93d1
Gitweb: http://git.kernel.org/tip/dcdb8807ba0f5127d4dc67daeeb154edf50a93d1
Author: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
AuthorDate: Sat, 15 Aug 2015 19:00:31 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Wed, 7 Oct 2015 16:02:50 -0700
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@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 7 +++---
kernel/rcu/tree_plugin.h | 61 +-----------------------------------------------
2 files changed, 5 insertions(+), 63 deletions(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index ae582e3..f44f4b3 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3654,7 +3654,8 @@ static void synchronize_sched_expedited_cpu_stop(void *data)
* Select the nodes that the upcoming expedited grace period needs
* to wait for.
*/
-static void sync_sched_exp_select_cpus(struct rcu_state *rsp)
+static void sync_rcu_exp_select_cpus(struct rcu_state *rsp,
+ smp_call_func_t func)
{
int cpu;
unsigned long flags;
@@ -3696,7 +3697,7 @@ static void sync_sched_exp_select_cpus(struct rcu_state *rsp)
for (cpu = rnp->grplo; cpu <= rnp->grphi; cpu++, mask <<= 1) {
if (!(mask_ofl_ipi & mask))
continue;
- ret = smp_call_function_single(cpu, synchronize_sched_expedited_cpu_stop, NULL, 0);
+ ret = smp_call_function_single(cpu, func, rsp, 0);
if (!ret)
mask_ofl_ipi &= ~mask;
}
@@ -3788,7 +3789,7 @@ void synchronize_sched_expedited(void)
return; /* Someone else did our work for us. */
rcu_exp_gp_seq_start(rsp);
- sync_sched_exp_select_cpus(rsp);
+ sync_rcu_exp_select_cpus(rsp, synchronize_sched_expedited_cpu_stop);
synchronize_sched_expedited_wait(rsp);
rcu_exp_gp_seq_end(rsp);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 7880202..6cbfbfc 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);
--
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