[PATCH] rcu: Remove deprecated RCU debugfs tracing code

From: Byungchul Park
Date: Fri Mar 02 2018 - 02:40:08 EST


Commit ae91aa0adb14(rcu: Remove debugfs tracing) removed the RCU debugfs
tracing code, and left deprecated code.

Because exp_workdone{0,1,2,3} won't be used anymore since the commit,
it's better to remove code to do with those variables. Remove it.

Signed-off-by: Byungchul Park <byungchul.park@xxxxxxx>
---
kernel/rcu/tree.h | 4 ----
kernel/rcu/tree_exp.h | 13 +++++--------
2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index 9dd0ea7..cfeb351 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -234,10 +234,6 @@ struct rcu_data {
#ifdef CONFIG_RCU_FAST_NO_HZ
struct rcu_head oom_head;
#endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */
- atomic_long_t exp_workdone0; /* # done by workqueue. */
- atomic_long_t exp_workdone1; /* # done by others #1. */
- atomic_long_t exp_workdone2; /* # done by others #2. */
- atomic_long_t exp_workdone3; /* # done by others #3. */
int exp_dynticks_snap; /* Double-check need for IPI. */

/* 6) Callback offloading. */
diff --git a/kernel/rcu/tree_exp.h b/kernel/rcu/tree_exp.h
index 73e1d3d..f8e4571 100644
--- a/kernel/rcu/tree_exp.h
+++ b/kernel/rcu/tree_exp.h
@@ -248,14 +248,12 @@ static void rcu_report_exp_rdp(struct rcu_state *rsp, struct rcu_data *rdp,
}

/* Common code for synchronize_{rcu,sched}_expedited() work-done checking. */
-static bool sync_exp_work_done(struct rcu_state *rsp, atomic_long_t *stat,
- unsigned long s)
+static bool sync_exp_work_done(struct rcu_state *rsp, unsigned long s)
{
if (rcu_exp_gp_seq_done(rsp, s)) {
trace_rcu_exp_grace_period(rsp->name, s, TPS("done"));
/* Ensure test happens before caller kfree(). */
smp_mb__before_atomic(); /* ^^^ */
- atomic_long_inc(stat);
return true;
}
return false;
@@ -289,7 +287,7 @@ static bool exp_funnel_lock(struct rcu_state *rsp, unsigned long s)
* promoting locality and is not strictly needed for correctness.
*/
for (; rnp != NULL; rnp = rnp->parent) {
- if (sync_exp_work_done(rsp, &rdp->exp_workdone1, s))
+ if (sync_exp_work_done(rsp, s))
return true;

/* Work not done, either wait here or go up. */
@@ -302,8 +300,7 @@ static bool exp_funnel_lock(struct rcu_state *rsp, unsigned long s)
rnp->grplo, rnp->grphi,
TPS("wait"));
wait_event(rnp->exp_wq[rcu_seq_ctr(s) & 0x3],
- sync_exp_work_done(rsp,
- &rdp->exp_workdone2, s));
+ sync_exp_work_done(rsp, s));
return true;
}
rnp->exp_seq_rq = s; /* Followers can wait on us. */
@@ -313,7 +310,7 @@ static bool exp_funnel_lock(struct rcu_state *rsp, unsigned long s)
}
mutex_lock(&rsp->exp_mutex);
fastpath:
- if (sync_exp_work_done(rsp, &rdp->exp_workdone3, s)) {
+ if (sync_exp_work_done(rsp, s)) {
mutex_unlock(&rsp->exp_mutex);
return true;
}
@@ -661,7 +658,7 @@ static void _synchronize_rcu_expedited(struct rcu_state *rsp,
rdp = per_cpu_ptr(rsp->rda, raw_smp_processor_id());
rnp = rcu_get_root(rsp);
wait_event(rnp->exp_wq[rcu_seq_ctr(s) & 0x3],
- sync_exp_work_done(rsp, &rdp->exp_workdone0, s));
+ sync_exp_work_done(rsp, s));
smp_mb(); /* Workqueue actions happen before return. */

/* Let the next expedited grace period start. */
--
1.9.1