From: Frederic Weisbecker <frede...@kernel.org>
RCU core can't be running anymore while in the middle of (de-)offloading
since this sort of transition now only applies to offline CPUs.
The SEGCBLIST_RCU_CORE state can therefore be removed.
Signed-off-by: Frederic Weisbecker <frede...@kernel.org>
Signed-off-by: Paul E. McKenney <paul...@kernel.org>
Reviewed-by: Paul E. McKenney <paul...@kernel.org>
Signed-off-by: Neeraj Upadhyay <neeraj.upadh...@kernel.org>
---
include/linux/rcu_segcblist.h | 9 ++++-----
kernel/rcu/rcu_segcblist.h | 9 ---------
kernel/rcu/tree.c | 3 ---
kernel/rcu/tree_nocb.h | 9 ---------
4 files changed, 4 insertions(+), 26 deletions(-)
diff --git a/include/linux/rcu_segcblist.h b/include/linux/rcu_segcblist.h
index ba95c06675e1..5469c54cd778 100644
--- a/include/linux/rcu_segcblist.h
+++ b/include/linux/rcu_segcblist.h
@@ -185,11 +185,10 @@ struct rcu_cblist {
*
----------------------------------------------------------------------------
*/
#define SEGCBLIST_ENABLED BIT(0)
-#define SEGCBLIST_RCU_CORE BIT(1)
-#define SEGCBLIST_LOCKING BIT(2)
-#define SEGCBLIST_KTHREAD_CB BIT(3)
-#define SEGCBLIST_KTHREAD_GP BIT(4)
-#define SEGCBLIST_OFFLOADED BIT(5)
+#define SEGCBLIST_LOCKING BIT(1)
+#define SEGCBLIST_KTHREAD_CB BIT(2)
+#define SEGCBLIST_KTHREAD_GP BIT(3)
+#define SEGCBLIST_OFFLOADED BIT(4)
struct rcu_segcblist {
struct rcu_head *head;
diff --git a/kernel/rcu/rcu_segcblist.h b/kernel/rcu/rcu_segcblist.h
index 4fe877f5f654..7a0962dfee86 100644
--- a/kernel/rcu/rcu_segcblist.h
+++ b/kernel/rcu/rcu_segcblist.h
@@ -95,15 +95,6 @@ static inline bool rcu_segcblist_is_offloaded(struct
rcu_segcblist *rsclp)
return false;
}
-static inline bool rcu_segcblist_completely_offloaded(struct rcu_segcblist
*rsclp)
-{
- if (IS_ENABLED(CONFIG_RCU_NOCB_CPU) &&
- !rcu_segcblist_test_flags(rsclp, SEGCBLIST_RCU_CORE))
- return true;
-
- return false;
-}
-
/*
* Are all segments following the specified segment of the specified
* rcu_segcblist structure empty of callbacks? (The specified
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 1a272c678533..82e831b969e4 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -79,9 +79,6 @@ static void rcu_sr_normal_gp_cleanup_work(struct work_struct
*);
static DEFINE_PER_CPU_SHARED_ALIGNED(struct rcu_data, rcu_data) = {
.gpwrap = true,
-#ifdef CONFIG_RCU_NOCB_CPU
- .cblist.flags = SEGCBLIST_RCU_CORE,
-#endif
};
static struct rcu_state rcu_state = {
.level = { &rcu_state.node[0] },
diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
index af44e75eb0cd..24daf606de0c 100644
--- a/kernel/rcu/tree_nocb.h
+++ b/kernel/rcu/tree_nocb.h
@@ -1060,7 +1060,6 @@ static int rcu_nocb_rdp_deoffload(struct rcu_data *rdp)
WARN_ON_ONCE(rcu_cblist_n_cbs(&rdp->nocb_bypass));
WARN_ON_ONCE(rcu_segcblist_n_cbs(&rdp->cblist));
- rcu_segcblist_set_flags(cblist, SEGCBLIST_RCU_CORE);
wake_gp = rdp_offload_toggle(rdp, false, flags);
mutex_lock(&rdp_gp->nocb_gp_kthread_mutex);
@@ -1168,13 +1167,6 @@ static int rcu_nocb_rdp_offload(struct rcu_data *rdp)
swait_event_exclusive(rdp->nocb_state_wq,
rcu_segcblist_test_flags(cblist,
SEGCBLIST_KTHREAD_GP));
- /*
- * All kthreads are ready to work, we can finally enable nocb bypass.
- */
- rcu_nocb_lock_irqsave(rdp, flags);
- rcu_segcblist_clear_flags(cblist, SEGCBLIST_RCU_CORE);
- rcu_nocb_unlock_irqrestore(rdp, flags);
-
return 0;
}
@@ -1350,7 +1342,6 @@ void __init rcu_init_nohz(void)
rcu_segcblist_init(&rdp->cblist);
rcu_segcblist_offload(&rdp->cblist, true);
rcu_segcblist_set_flags(&rdp->cblist, SEGCBLIST_KTHREAD_GP);
- rcu_segcblist_clear_flags(&rdp->cblist, SEGCBLIST_RCU_CORE);
}
rcu_organize_nocb_kthreads();
}
--
2.40.1
