[PATCH 04/34] rcu: Remove ->trc_holdout_list from task_struct

["Paul E. McKenney" <paulmck@kernel.org>]

Now that RCU Tasks Trace has been re-implemented in terms of SRCU-fast,
the ->trc_holdout_list task_struct field is only initialized, and never
actually used.  This commit therefore removes it.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <bpf@vger.kernel.org>
---
 include/linux/sched.h | 1 -
 init/init_task.c      | 1 -
 kernel/fork.c         | 1 -
 3 files changed, 3 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3f840cfa941132..e62c99e44a5502 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -941,7 +941,6 @@ struct task_struct {
 	int				trc_reader_nesting;
 	struct srcu_ctr __percpu	*trc_reader_scp;
 	union rcu_special		trc_reader_special;
-	struct list_head		trc_holdout_list;
 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
 
 	struct sched_info		sched_info;
diff --git a/init/init_task.c b/init/init_task.c
index dd6226251689c8..91c37f66ec8e9a 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -166,7 +166,6 @@ struct task_struct init_task __aligned(L1_CACHE_BYTES) = {
 #ifdef CONFIG_TASKS_TRACE_RCU
 	.trc_reader_nesting = 0,
 	.trc_reader_special.s = 0,
-	.trc_holdout_list = LIST_HEAD_INIT(init_task.trc_holdout_list),
 #endif
 #ifdef CONFIG_CPUSETS
 	.mems_allowed_seq = SEQCNT_SPINLOCK_ZERO(init_task.mems_allowed_seq,
diff --git a/kernel/fork.c b/kernel/fork.c
index 69d34c123b9e5f..12388e895d2955 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1781,7 +1781,6 @@ static inline void rcu_copy_process(struct task_struct *p)
 #ifdef CONFIG_TASKS_TRACE_RCU
 	p->trc_reader_nesting = 0;
 	p->trc_reader_special.s = 0;
-	INIT_LIST_HEAD(&p->trc_holdout_list);
 #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */
 }
 
-- 
2.40.1