[PATCH V2 3/7] rcu: remove useless special.b.deferred_qs

[Lai Jiangshan]

->read_read_unlock_special.b.deferred_qs is set when
->read_read_unlock_special is non-zero, and it is cleared when
->read_read_unlock_special is cleared.

So it is useless.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
 include/linux/sched.h    | 2 +-
 kernel/rcu/tree_plugin.h | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2c2e56bd8913..3ba392d71de9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -604,7 +604,7 @@ union rcu_special {
 		u8			blocked;
 		u8			need_qs;
 		u8			exp_hint; /* Hint for performance. */
-		u8			deferred_qs;
+		u8			pad; /* No garbage from compiler! */
 	} b; /* Bits. */
 	u32 s; /* Set of bits. */
 };
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 2fab8be2061f..f2fd7d687bdb 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -622,7 +622,6 @@ static void rcu_read_unlock_special(struct task_struct *t)
 				irq_work_queue_on(&rdp->defer_qs_iw, rdp->cpu);
 			}
 		}
-		t->rcu_read_unlock_special.b.deferred_qs = true;
 		local_irq_restore(flags);
 		return;
 	}
-- 
2.20.1