rcu: Remove CONFIG_PROVE_RCU_DELAY

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@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
[ paulmck: Remove definition and uses as noted by Paul Bolle. ]
This commit is contained in:
Paul E. McKenney 2014-06-23 12:09:52 -07:00
parent d860d40327
commit 11992c703a
19 changed files with 0 additions and 38 deletions

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@ -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();
}

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@ -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);

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@ -1131,20 +1131,6 @@ config PROVE_RCU_REPEATEDLY
Say N if you are unsure.
config PROVE_RCU_DELAY
bool "RCU debugging: preemptible RCU race provocation"
depends on DEBUG_KERNEL && PREEMPT_RCU
default n
help
There is a class of races that involve an unlikely preemption
of __rcu_read_unlock() just after ->rcu_read_lock_nesting has
been set to INT_MIN. This feature inserts a delay at that
point to increase the probability of these races.
Say Y to increase probability of preemption of __rcu_read_unlock().
Say N if you are unsure.
config SPARSE_RCU_POINTER
bool "RCU debugging: sparse-based checks for pointer usage"
default n

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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

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@ -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

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@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y
#CHECK#CONFIG_TREE_PREEMPT_RCU=y
CONFIG_DEBUG_KERNEL=y
CONFIG_PROVE_RCU_DELAY=y
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_RT_MUTEXES=y

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@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y
#CHECK#CONFIG_TREE_PREEMPT_RCU=y
CONFIG_DEBUG_KERNEL=y
CONFIG_PROVE_RCU_DELAY=y
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_RT_MUTEXES=y

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@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y
#CHECK#CONFIG_TREE_PREEMPT_RCU=y
CONFIG_DEBUG_KERNEL=y
CONFIG_PROVE_RCU_DELAY=y
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_RT_MUTEXES=y

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@ -13,7 +13,6 @@ CONFIG_PREEMPT_VOLUNTARY=n
CONFIG_PREEMPT=y
#CHECK#CONFIG_TREE_PREEMPT_RCU=y
CONFIG_DEBUG_KERNEL=y
CONFIG_PROVE_RCU_DELAY=y
CONFIG_DEBUG_OBJECTS=y
CONFIG_DEBUG_OBJECTS_RCU_HEAD=y
CONFIG_RT_MUTEXES=y

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@ -14,7 +14,6 @@ CONFIG_NO_HZ_FULL_SYSIDLE -- Do one.
CONFIG_PREEMPT -- Do half. (First three and #8.)
CONFIG_PROVE_LOCKING -- Do all but two, covering CONFIG_PROVE_RCU and not.
CONFIG_PROVE_RCU -- Do all but one under CONFIG_PROVE_LOCKING.
CONFIG_PROVE_RCU_DELAY -- Do one.
CONFIG_RCU_BOOST -- one of TREE_PREEMPT_RCU.
CONFIG_RCU_BOOST_PRIO -- set to 2 for _BOOST testing.
CONFIG_RCU_CPU_STALL_INFO -- do one with and without _VERBOSE.