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authorPeter Zijlstra <peterz@infradead.org>2020-08-07 20:53:16 +0200
committerPeter Zijlstra <peterz@infradead.org>2020-08-26 12:41:56 +0200
commiteb1f00237aca2e368b93db79303f8433d1976d10 (patch)
tree4923e5e3564921099b83b1f791e83507175c59ef /kernel/locking
parent044d0d6de9f50192f9697583504a382347ee95ca (diff)
downloadlinux-eb1f00237aca2e368b93db79303f8433d1976d10.tar.bz2
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
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/lockdep.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index c872e95e6e4d..54b74fabf40c 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -4977,6 +4977,8 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
{
unsigned long flags;
+ trace_lock_acquire(lock, subclass, trylock, read, check, nest_lock, ip);
+
if (unlikely(current->lockdep_recursion)) {
/* XXX allow trylock from NMI ?!? */
if (lockdep_nmi() && !trylock) {
@@ -5001,7 +5003,6 @@ void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
check_flags(flags);
current->lockdep_recursion++;
- 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, 0);
lockdep_recursion_finish();
@@ -5013,13 +5014,15 @@ void lock_release(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
+ trace_lock_release(lock, ip);
+
if (unlikely(current->lockdep_recursion))
return;
raw_local_irq_save(flags);
check_flags(flags);
+
current->lockdep_recursion++;
- trace_lock_release(lock, ip);
if (__lock_release(lock, ip))
check_chain_key(current);
lockdep_recursion_finish();
@@ -5205,8 +5208,6 @@ __lock_acquired(struct lockdep_map *lock, unsigned long ip)
hlock->holdtime_stamp = now;
}
- trace_lock_acquired(lock, ip);
-
stats = get_lock_stats(hlock_class(hlock));
if (waittime) {
if (hlock->read)
@@ -5225,6 +5226,8 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
+ trace_lock_acquired(lock, ip);
+
if (unlikely(!lock_stat || !debug_locks))
return;
@@ -5234,7 +5237,6 @@ void lock_contended(struct lockdep_map *lock, unsigned long ip)
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion++;
- trace_lock_contended(lock, ip);
__lock_contended(lock, ip);
lockdep_recursion_finish();
raw_local_irq_restore(flags);
@@ -5245,6 +5247,8 @@ void lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
+ trace_lock_contended(lock, ip);
+
if (unlikely(!lock_stat || !debug_locks))
return;