[PATCH tip/core/rcu 14/17] rcu: remove CONFIG_PROVE_RCU_DELAY

From: Paul E. McKenney
Date: Mon Jul 07 2014 - 18:39:42 EST

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From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>

The CONFIG_PROVE_RCU_DELAY Kconfig parameter doesn't appear to be very
effective at finding race conditions, so this commit removes it.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 5 -----
kernel/rcu/update.c | 3 ---
tools/testing/selftests/rcutorture/configs/rcu/TREE01 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE02 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE02-T | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE03 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE04 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE05 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE06 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE07 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE08 | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE08-T | 1 -
tools/testing/selftests/rcutorture/configs/rcu/TREE09 | 1 -
13 files changed, 19 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index a6c5424ffa38..1b70cb6fbe3c 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1647,11 +1647,6 @@ static int rcu_gp_init(struct rcu_state *rsp)
rnp->level, rnp->grplo,
rnp->grphi, rnp->qsmask);
raw_spin_unlock_irq(&rnp->lock);
-#ifdef CONFIG_PROVE_RCU_DELAY
- if ((prandom_u32() % (rcu_num_nodes + 1)) == 0 &&
- system_state == SYSTEM_RUNNING)
- udelay(200);
-#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
cond_resched();
}

diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c
index bc7883570530..4056d7992a6c 100644
--- a/kernel/rcu/update.c
+++ b/kernel/rcu/update.c
@@ -90,9 +90,6 @@ void __rcu_read_unlock(void)
} else {
barrier(); /* critical section before exit code. */
t->rcu_read_lock_nesting = INT_MIN;
-#ifdef CONFIG_PROVE_RCU_DELAY
- udelay(10); /* Make preemption more probable. */
-#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
barrier(); /* assign before ->rcu_read_unlock_special load */
if (unlikely(ACCESS_ONCE(t->rcu_read_unlock_special)))
rcu_read_unlock_special(t);
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE01 b/tools/testing/selftests/rcutorture/configs/rcu/TREE01
index 9c827ec59a97..063b7079c621 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE01
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE01
@@ -15,7 +15,6 @@ CONFIG_RCU_FANOUT_EXACT=n
CONFIG_RCU_NOCB_CPU=y
CONFIG_RCU_NOCB_CPU_ZERO=y
CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE02 b/tools/testing/selftests/rcutorture/configs/rcu/TREE02
index 1a777b5f68b5..ea119ba2f7d4 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE02
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE02
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_EXACT=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=y
CONFIG_RCU_BOOST=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T b/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T
index 61c8d9ce5bb2..19cf9485f48a 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_EXACT=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=y
CONFIG_RCU_BOOST=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE03 b/tools/testing/selftests/rcutorture/configs/rcu/TREE03
index c1f111c1561b..f4567fb3e332 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE03
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE03
@@ -14,7 +14,6 @@ CONFIG_RCU_FANOUT_LEAF=4
CONFIG_RCU_FANOUT_EXACT=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE04 b/tools/testing/selftests/rcutorture/configs/rcu/TREE04
index 7dbd27ce17a4..0a262fbb0c12 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE04
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE04
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_LEAF=2
CONFIG_RCU_FANOUT_EXACT=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=y
CONFIG_RCU_CPU_STALL_VERBOSE=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE05 b/tools/testing/selftests/rcutorture/configs/rcu/TREE05
index d0f32e574743..3a06b97e9a73 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE05
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE05
@@ -18,7 +18,6 @@ CONFIG_RCU_NOCB_CPU_NONE=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU=y
-CONFIG_PROVE_RCU_DELAY=y
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE06 b/tools/testing/selftests/rcutorture/configs/rcu/TREE06
index 2e477dfb9c57..8f084cca91bf 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE06
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE06
@@ -19,7 +19,6 @@ CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_PROVE_RCU=y
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE07 b/tools/testing/selftests/rcutorture/configs/rcu/TREE07
index 042f86ef362a..ab6225506909 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE07
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE07
@@ -17,7 +17,6 @@ CONFIG_RCU_FANOUT_LEAF=2
CONFIG_RCU_FANOUT_EXACT=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=y
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_DEBUG_OBJECTS_RCU_HEAD=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08 b/tools/testing/selftests/rcutorture/configs/rcu/TREE08
index 3438cee1e3c5..69a2e255bf98 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE08
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_LEAF=2
CONFIG_RCU_NOCB_CPU=y
CONFIG_RCU_NOCB_CPU_ALL=y
CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T
index bf4523d3e44c..a0f32fb8f17e 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T
@@ -18,7 +18,6 @@ CONFIG_RCU_FANOUT_LEAF=2
CONFIG_RCU_NOCB_CPU=y
CONFIG_RCU_NOCB_CPU_ALL=y
CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
diff --git a/tools/testing/selftests/rcutorture/configs/rcu/TREE09 b/tools/testing/selftests/rcutorture/configs/rcu/TREE09
index 81e4f7c0bf0b..b7a62a540ad1 100644
--- a/tools/testing/selftests/rcutorture/configs/rcu/TREE09
+++ b/tools/testing/selftests/rcutorture/configs/rcu/TREE09
@@ -13,7 +13,6 @@ CONFIG_SUSPEND=n
CONFIG_HIBERNATION=n
CONFIG_RCU_NOCB_CPU=n
CONFIG_DEBUG_LOCK_ALLOC=n
-CONFIG_PROVE_RCU_DELAY=n
CONFIG_RCU_CPU_STALL_INFO=n
CONFIG_RCU_CPU_STALL_VERBOSE=n
CONFIG_RCU_BOOST=n
--
1.8.1.5

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Next message: Paul E. McKenney: "[PATCH tip/core/rcu 13/17] rcu: Use __this_cpu_read() instead of per_cpu_ptr()"
Previous message: Paul E. McKenney: "[PATCH tip/core/rcu 05/17] rcu: remove redundant ACCESS_ONCE() from tick_do_timer_cpu"
In reply to: Paul E. McKenney: "[PATCH tip/core/rcu 05/17] rcu: remove redundant ACCESS_ONCE() from tick_do_timer_cpu"
Next in thread: Paul E. McKenney: "[PATCH tip/core/rcu 13/17] rcu: Use __this_cpu_read() instead of per_cpu_ptr()"
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