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rcu: Consolidate expedited GP code into rcu_exp_wait_wake()

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Currently, synchronize_rcu_expedited() and rcu_sched_expedited() have
significant duplicate code.  This commit therefore consolidates some of
this code into rcu_exp_wake(), which is now renamed to rcu_exp_wait_wake()
in recognition of its added responsibilities.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney
2016-03-16 16:22:25 -07:00
parent 356051e1de
commit 4ea3e85b11
2 changed files with 11 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files
kernel/rcu/tree.c
+9 -9
View File
@@ -3839,14 +3839,18 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
} }
/* /*
* Wake up everyone who piggybacked on the just-completed expedited * Wait for the current expedited grace period to complete, and then
* wake up everyone who piggybacked on the just-completed expedited
* grace period. Also update all the ->exp_seq_rq counters as needed * grace period. Also update all the ->exp_seq_rq counters as needed
* in order to avoid counter-wrap problems. * in order to avoid counter-wrap problems.
*/ */
static void rcu_exp_wake(struct rcu_state *rsp, unsigned long s) static void rcu_exp_wait_wake(struct rcu_state *rsp, unsigned long s)
{ {
struct rcu_node *rnp; struct rcu_node *rnp;
synchronize_sched_expedited_wait(rsp);
rcu_exp_gp_seq_end(rsp);
trace_rcu_exp_grace_period(rsp->name, s, TPS("end"));
rcu_for_each_node_breadth_first(rsp, rnp) { rcu_for_each_node_breadth_first(rsp, rnp) {
if (ULONG_CMP_LT(READ_ONCE(rnp->exp_seq_rq), s)) { if (ULONG_CMP_LT(READ_ONCE(rnp->exp_seq_rq), s)) {
spin_lock(&rnp->exp_lock); spin_lock(&rnp->exp_lock);
@@ -3857,6 +3861,8 @@ static void rcu_exp_wake(struct rcu_state *rsp, unsigned long s)
} }
wake_up_all(&rnp->exp_wq[(rsp->expedited_sequence >> 1) & 0x1]); wake_up_all(&rnp->exp_wq[(rsp->expedited_sequence >> 1) & 0x1]);
} }
trace_rcu_exp_grace_period(rsp->name, s, TPS("endwake"));
mutex_unlock(&rsp->exp_mutex);
} }
/** /**
@@ -3904,13 +3910,7 @@ void synchronize_sched_expedited(void)
sync_rcu_exp_select_cpus(rsp, sync_sched_exp_handler); sync_rcu_exp_select_cpus(rsp, sync_sched_exp_handler);
/* Wait and clean up, including waking everyone. */ /* Wait and clean up, including waking everyone. */
synchronize_sched_expedited_wait(rsp); rcu_exp_wait_wake(rsp, s);
rcu_exp_gp_seq_end(rsp);
trace_rcu_exp_grace_period(rsp->name, s, TPS("end"));
rcu_exp_wake(rsp, s);
trace_rcu_exp_grace_period(rsp->name, s, TPS("endwake"));
mutex_unlock(&rsp->exp_mutex);
} }
EXPORT_SYMBOL_GPL(synchronize_sched_expedited); EXPORT_SYMBOL_GPL(synchronize_sched_expedited);
kernel/rcu/tree_plugin.h
+2 -8
View File
@@ -759,14 +759,8 @@ void synchronize_rcu_expedited(void)
/* Initialize the rcu_node tree in preparation for the wait. */ /* Initialize the rcu_node tree in preparation for the wait. */
sync_rcu_exp_select_cpus(rsp, sync_rcu_exp_handler); sync_rcu_exp_select_cpus(rsp, sync_rcu_exp_handler);
/* Wait for snapshotted ->blkd_tasks lists to drain. */ /* Wait for ->blkd_tasks lists to drain, then wake everyone up. */
synchronize_sched_expedited_wait(rsp); rcu_exp_wait_wake(rsp, s);
rcu_exp_gp_seq_end(rsp);
trace_rcu_exp_grace_period(rsp->name, s, TPS("end"));
rcu_exp_wake(rsp, s);
trace_rcu_exp_grace_period(rsp->name, s, TPS("endwake"));
mutex_unlock(&rsp->exp_mutex);
} }
EXPORT_SYMBOL_GPL(synchronize_rcu_expedited); EXPORT_SYMBOL_GPL(synchronize_rcu_expedited);