From: Oleg Nesterov <oleg@redhat.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Steven Rostedt <rostedt@goodmis.org>,
Paul McKenney <paulmck@linux.vnet.ibm.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: [PATCH 1/1] lockdep: Kill held_lock->check and "int check" arg of __lock_acquire()
Date: Sun, 12 Jan 2014 18:45:54 +0100 [thread overview]
Message-ID: <20140112174554.GB12147@redhat.com> (raw)
In-Reply-To: <20140112174532.GA12147@redhat.com>
The "int check" argument of lock_acquire() and held_lock->check
are misleading and unneeded. This is only used as a boolean, 2
denotes "true", everything else is "false". And this boolean is
always equal to prove_locking.
The only exception is __lockdep_no_validate__ which should make
this condition "false" in validate_chain().
This patch kills this member and removes the argument from
__lock_acquire(), the next patch will remove the now unused arg
from lock_acquire() and update its callers.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
include/linux/lockdep.h | 1 -
kernel/locking/lockdep.c | 22 ++++++++--------------
2 files changed, 8 insertions(+), 15 deletions(-)
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 92b1bfc..13bd13d 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -252,7 +252,6 @@ struct held_lock {
unsigned int trylock:1; /* 16 bits */
unsigned int read:2; /* see lock_acquire() comment */
- unsigned int check:2; /* see lock_acquire() comment */
unsigned int hardirqs_off:1;
unsigned int references:11; /* 32 bits */
};
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 576ba75..32ba948 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2096,7 +2096,8 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
* (If lookup_chain_cache() returns with 1 it acquires
* graph_lock for us)
*/
- if (!hlock->trylock && (hlock->check == 2) &&
+ if (!hlock->trylock && prove_locking &&
+ hlock_class(hlock)->key != __lockdep_no_validate__.subkeys &&
lookup_chain_cache(curr, hlock, chain_key)) {
/*
* Check whether last held lock:
@@ -3041,7 +3042,7 @@ static int __lock_is_held(struct lockdep_map *lock);
* We maintain the dependency maps and validate the locking attempt:
*/
static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
- int trylock, int read, int check, int hardirqs_off,
+ int trylock, int read, int hardirqs_off,
struct lockdep_map *nest_lock, unsigned long ip,
int references)
{
@@ -3053,9 +3054,6 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int class_idx;
u64 chain_key;
- if (!prove_locking)
- check = 1;
-
if (unlikely(!debug_locks))
return 0;
@@ -3067,9 +3065,6 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
- if (lock->key == &__lockdep_no_validate__)
- check = 1;
-
if (subclass < NR_LOCKDEP_CACHING_CLASSES)
class = lock->class_cache[subclass];
/*
@@ -3128,7 +3123,6 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->nest_lock = nest_lock;
hlock->trylock = trylock;
hlock->read = read;
- hlock->check = check;
hlock->hardirqs_off = !!hardirqs_off;
hlock->references = references;
#ifdef CONFIG_LOCK_STAT
@@ -3136,7 +3130,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->holdtime_stamp = lockstat_clock();
#endif
- if (check == 2 && !mark_irqflags(curr, hlock))
+ if (prove_locking && !mark_irqflags(curr, hlock))
return 0;
/* mark it as used: */
@@ -3338,7 +3332,7 @@ found_it:
hlock = curr->held_locks + i;
if (!__lock_acquire(hlock->instance,
hlock_class(hlock)->subclass, hlock->trylock,
- hlock->read, hlock->check, hlock->hardirqs_off,
+ hlock->read, hlock->hardirqs_off,
hlock->nest_lock, hlock->acquire_ip,
hlock->references))
return 0;
@@ -3422,7 +3416,7 @@ found_it:
hlock = curr->held_locks + i;
if (!__lock_acquire(hlock->instance,
hlock_class(hlock)->subclass, hlock->trylock,
- hlock->read, hlock->check, hlock->hardirqs_off,
+ hlock->read, hlock->hardirqs_off,
hlock->nest_lock, hlock->acquire_ip,
hlock->references))
return 0;
@@ -3598,8 +3592,8 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
current->lockdep_recursion = 1;
trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
- __lock_acquire(lock, subclass, trylock, read, check,
- irqs_disabled_flags(flags), nest_lock, ip, 0);
+ __lock_acquire(lock, subclass, trylock, read,
+ irqs_disabled_flags(flags), nest_lock, ip, 0);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
--
1.5.5.1
next prev parent reply other threads:[~2014-01-12 17:45 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-09 11:15 [RFC][PATCH] lockdep: Introduce wait-type checks Peter Zijlstra
2014-01-09 11:49 ` Peter Zijlstra
2014-01-09 16:31 ` Oleg Nesterov
2014-01-09 17:08 ` Peter Zijlstra
2014-01-09 17:54 ` check && lockdep_no_validate (Was: lockdep: Introduce wait-type checks) Oleg Nesterov
2014-01-12 20:58 ` Peter Zijlstra
2014-01-13 16:07 ` Oleg Nesterov
2014-01-16 17:43 ` Oleg Nesterov
2014-01-16 18:09 ` Peter Zijlstra
2014-01-16 20:26 ` Alan Stern
2014-01-17 16:31 ` Oleg Nesterov
2014-01-17 18:01 ` Alan Stern
2014-01-20 18:19 ` [PATCH 0/5] lockdep: (Was: check && lockdep_no_validate) Oleg Nesterov
2014-01-20 18:20 ` [PATCH 1/5] lockdep: make held_lock->check and "int check" argument bool Oleg Nesterov
2014-02-10 13:32 ` [tip:core/locking] lockdep: Make " tip-bot for Oleg Nesterov
2014-01-20 18:20 ` [PATCH 2/5] lockdep: don't create the wrong dependency on hlock->check == 0 Oleg Nesterov
2014-02-10 13:33 ` [tip:core/locking] lockdep: Don' t " tip-bot for Oleg Nesterov
2014-01-20 18:20 ` [PATCH 3/5] lockdep: change mark_held_locks() to check hlock->check instead of lockdep_no_validate Oleg Nesterov
2014-02-10 13:33 ` [tip:core/locking] lockdep: Change " tip-bot for Oleg Nesterov
2014-01-20 18:20 ` [PATCH 4/5] lockdep: change lockdep_set_novalidate_class() to use _and_name Oleg Nesterov
2014-02-10 13:33 ` [tip:core/locking] lockdep: Change " tip-bot for Oleg Nesterov
2014-01-20 18:20 ` [PATCH 5/5] lockdep: pack subclass/trylock/read/check into a single argument Oleg Nesterov
2014-01-21 14:10 ` Peter Zijlstra
2014-01-21 17:27 ` Oleg Nesterov
2014-01-21 17:35 ` Dave Jones
2014-01-21 18:43 ` Oleg Nesterov
2014-01-21 18:53 ` Steven Rostedt
2014-01-21 20:06 ` Oleg Nesterov
2014-01-21 19:39 ` uninline rcu_lock_acquire/etc ? Oleg Nesterov
2014-01-22 3:54 ` Paul E. McKenney
2014-01-22 18:31 ` Oleg Nesterov
2014-01-22 19:34 ` Paul E. McKenney
2014-01-22 19:39 ` Oleg Nesterov
2014-01-20 18:37 ` [PATCH 0/5] lockdep: (Was: check && lockdep_no_validate) Alan Stern
2014-01-20 18:54 ` Oleg Nesterov
2014-01-20 21:42 ` Alan Stern
2014-01-12 9:40 ` [RFC][PATCH] lockdep: Introduce wait-type checks Ingo Molnar
2014-01-12 17:45 ` [PATCH 0/1] lockdep: Kill held_lock->check and "int check" arg of __lock_acquire() Oleg Nesterov
2014-01-12 17:45 ` Oleg Nesterov [this message]
2014-01-13 0:28 ` [PATCH 1/1] " Dave Jones
2014-01-13 16:20 ` Oleg Nesterov
2014-01-13 17:06 ` Oleg Nesterov
2014-01-13 17:28 ` Peter Zijlstra
2014-01-13 18:52 ` Oleg Nesterov
2014-01-13 22:34 ` Paul E. McKenney
2014-01-12 20:00 ` [PATCH 0/1] " Peter Zijlstra
2014-01-13 18:35 ` Oleg Nesterov
2014-01-09 17:33 ` [RFC][PATCH] lockdep: Introduce wait-type checks Dave Jones
2014-01-09 22:12 ` Peter Zijlstra
2014-01-10 12:11 ` Peter Zijlstra
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