The rcu_preempt_note_context_switch() tries to handle cases where
__rcu_read_unlock() got preempted and then the context switch path does
the reporting of the quiscent state along with clearing any bits in the
rcu_read_unlock_special union.
This can be handled by just calling rcu_deferred_qs() which was added
during the RCU consolidation work and already does these checks.
Tested RCU config TREE03 for an hour which succeeds.
Cc: rcu@xxxxxxxxxxxxxxx
Cc: kernel-team@xxxxxxxxxxx
Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree_plugin.h | 9 ---------
1 file changed, 9 deletions(-)
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index bff6410fac06..ebb4d46a6267 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -313,15 +313,6 @@ void rcu_note_context_switch(bool preempt)
? rnp->gp_seq
: rcu_seq_snap(&rnp->gp_seq));
rcu_preempt_ctxt_queue(rnp, rdp);
- } else if (t->rcu_read_lock_nesting < 0 &&
- t->rcu_read_unlock_special.s) {
-
- /*
- * Complete exit from RCU read-side critical section on
- * behalf of preempted instance of __rcu_read_unlock().
- */
- rcu_read_unlock_special(t);
- rcu_preempt_deferred_qs(t);
} else {
rcu_preempt_deferred_qs(t);
}
--
2.22.0.410.gd8fdbe21b5-goog
