From: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
This commit stops using ->srcu_idx for rcutorture's reader-batch
consistency checking, using ->srcu_gp_seq instead. This is a first
step towards a faster srcu_read_{,un}lock_lite() that avoids the array
accesses that use ->srcu_idx.
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Andrii Nakryiko <andrii@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: <bpf@xxxxxxxxxxxxxxx>
Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx>
---
kernel/rcu/rcutorture.c | 2 ++
kernel/rcu/srcutree.c | 2 +-
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index d26fb1d33ed9..1d2de50fb5d6 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -791,6 +791,7 @@ static struct rcu_torture_ops srcu_ops = {
.readunlock = srcu_torture_read_unlock,
.readlock_held = torture_srcu_read_lock_held,
.get_gp_seq = srcu_torture_completed,
+ .gp_diff = rcu_seq_diff,
.deferred_free = srcu_torture_deferred_free,
.sync = srcu_torture_synchronize,
.exp_sync = srcu_torture_synchronize_expedited,
@@ -834,6 +835,7 @@ static struct rcu_torture_ops srcud_ops = {
.readunlock = srcu_torture_read_unlock,
.readlock_held = torture_srcu_read_lock_held,
.get_gp_seq = srcu_torture_completed,
+ .gp_diff = rcu_seq_diff,
.deferred_free = srcu_torture_deferred_free,
.sync = srcu_torture_synchronize,
.exp_sync = srcu_torture_synchronize_expedited,
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index b83c74c4dcc0..e69ce9d59abf 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -1675,7 +1675,7 @@ EXPORT_SYMBOL_GPL(srcu_barrier);
*/
unsigned long srcu_batches_completed(struct srcu_struct *ssp)
{
- return READ_ONCE(ssp->srcu_idx);
+ return READ_ONCE(ssp->srcu_sup->srcu_gp_seq);
}
EXPORT_SYMBOL_GPL(srcu_batches_completed);
--
2.39.5 (Apple Git-154)
