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| author | Peter Zijlstra <peterz@infradead.org> | 2020-08-07 20:53:16 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2020-08-26 12:41:56 +0200 |
| commit | eb1f00237aca2e368b93db79303f8433d1976d10 (patch) | |
| tree | 4923e5e3564921099b83b1f791e83507175c59ef /kernel | |
| parent | 044d0d6de9f50192f9697583504a382347ee95ca (diff) | |
| download | linux-stable-eb1f00237aca2e368b93db79303f8433d1976d10.tar.gz linux-stable-eb1f00237aca2e368b93db79303f8433d1976d10.tar.bz2 linux-stable-eb1f00237aca2e368b93db79303f8433d1976d10.zip | |
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')
| -rw-r--r-- | kernel/locking/lockdep.c | 14 |
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; |