lockdep,trace: Expose tracepoints

The lockdep tracepoints are under the lockdep recursion counter, this
has a bunch of nasty side effects:

 - TRACE_IRQFLAGS doesn't work across the entire tracepoint

 - RCU-lockdep doesn't see the tracepoints either, hiding numerous
   "suspicious RCU usage" warnings.

Pull the trace_lock_*() tracepoints completely out from under the
lockdep recursion handling and completely rely on the trace level
recusion handling -- also, tracing *SHOULD* not be taking locks in any
case.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Marco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200821085348.782688941@infradead.org
This commit is contained in:
Peter Zijlstra 2020-08-07 20:53:16 +02:00
parent 044d0d6de9
commit eb1f00237a

View File

@ -4977,6 +4977,8 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
{ {
unsigned long flags; unsigned long flags;
trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
if (unlikely(current->lockdep_recursion)) { if (unlikely(current->lockdep_recursion)) {
/* XXX allow trylock from NMI ?!? */ /* XXX allow trylock from NMI ?!? */
if (lockdep_nmi() && !trylock) { if (lockdep_nmi() && !trylock) {
@ -5001,7 +5003,6 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
check_flags(flags); check_flags(flags);
current->lockdep_recursion++; current->lockdep_recursion++;
trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
__lock_acquire(lock, subclass, trylock, read, check, __lock_acquire(lock, subclass, trylock, read, check,
irqs_disabled_flags(flags), nest_lock, ip, 0, 0); irqs_disabled_flags(flags), nest_lock, ip, 0, 0);
lockdep_recursion_finish(); lockdep_recursion_finish();
@ -5013,13 +5014,15 @@ void lock_release(struct lockdep_map *lock, unsigned long ip)
{ {
unsigned long flags; unsigned long flags;
trace_lock_release(lock, ip);
if (unlikely(current->lockdep_recursion)) if (unlikely(current->lockdep_recursion))
return; return;
raw_local_irq_save(flags); raw_local_irq_save(flags);
check_flags(flags); check_flags(flags);
current->lockdep_recursion++; current->lockdep_recursion++;
trace_lock_release(lock, ip);
if (__lock_release(lock, ip)) if (__lock_release(lock, ip))
check_chain_key(current); check_chain_key(current);
lockdep_recursion_finish(); lockdep_recursion_finish();
@ -5205,8 +5208,6 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
hlock->holdtime_stamp = now; hlock->holdtime_stamp = now;
} }
trace_lock_acquired(lock, ip);
stats = get_lock_stats(hlock_class(hlock)); stats = get_lock_stats(hlock_class(hlock));
if (waittime) { if (waittime) {
if (hlock->read) if (hlock->read)
@ -5225,6 +5226,8 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
{ {
unsigned long flags; unsigned long flags;
trace_lock_acquired(lock, ip);
if (unlikely(!lock_stat || !debug_locks)) if (unlikely(!lock_stat || !debug_locks))
return; return;
@ -5234,7 +5237,6 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
raw_local_irq_save(flags); raw_local_irq_save(flags);
check_flags(flags); check_flags(flags);
current->lockdep_recursion++; current->lockdep_recursion++;
trace_lock_contended(lock, ip);
__lock_contended(lock, ip); __lock_contended(lock, ip);
lockdep_recursion_finish(); lockdep_recursion_finish();
raw_local_irq_restore(flags); raw_local_irq_restore(flags);
@ -5245,6 +5247,8 @@ void lock_acquired(struct lockdep_map *lock, unsigned long ip)
{ {
unsigned long flags; unsigned long flags;
trace_lock_contended(lock, ip);
if (unlikely(!lock_stat || !debug_locks)) if (unlikely(!lock_stat || !debug_locks))
return; return;