Merge tag 'locking-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:

 - rwsem cleanups & optimizations/fixes:
    - Conditionally wake waiters in reader/writer slowpaths
    - Always try to wake waiters in out_nolock path

 - Add try_cmpxchg64() implementation, with arch optimizations - and use
   it to micro-optimize sched_clock_{local,remote}()

 - Various force-inlining fixes to address objdump instrumentation-check
   warnings

 - Add lock contention tracepoints:

    lock:contention_begin
    lock:contention_end

 - Misc smaller fixes & cleanups

* tag 'locking-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/clock: Use try_cmpxchg64 in sched_clock_{local,remote}
  locking/atomic/x86: Introduce arch_try_cmpxchg64
  locking/atomic: Add generic try_cmpxchg64 support
  futex: Remove a PREEMPT_RT_FULL reference.
  locking/qrwlock: Change "queue rwlock" to "queued rwlock"
  lockdep: Delete local_irq_enable_in_hardirq()
  locking/mutex: Make contention tracepoints more consistent wrt adaptive spinning
  locking: Apply contention tracepoints in the slow path
  locking: Add lock contention tracepoints
  locking/rwsem: Always try to wake waiters in out_nolock path
  locking/rwsem: Conditionally wake waiters in reader/writer slowpaths
  locking/rwsem: No need to check for handoff bit if wait queue empty
  lockdep: Fix -Wunused-parameter for _THIS_IP_
  x86/mm: Force-inline __phys_addr_nodebug()
  x86/kvm/svm: Force-inline GHCB accessors
  task_stack, x86/cea: Force-inline stack helpers

1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/locking/rwbase_rt.c b/kernel/locking/rwbase_rt.c
index 6fd3162e4098..c201aadb9301 100644
--- a/kernel/locking/rwbase_rt.c
+++ b/kernel/locking/rwbase_rt.c
@@ -112,6 +112,8 @@ static int __sched __rwbase_read_lock(struct rwbase_rt *rwb,
 	 * Reader2 to call up_read(), which might be unbound.
 	 */
 
+	trace_contention_begin(rwb, LCB_F_RT | LCB_F_READ);
+
 	/*
 	 * For rwlocks this returns 0 unconditionally, so the below
 	 * !ret conditionals are optimized out.
@@ -130,6 +132,8 @@ static int __sched __rwbase_read_lock(struct rwbase_rt *rwb,
 	raw_spin_unlock_irq(&rtm->wait_lock);
 	if (!ret)
 		rwbase_rtmutex_unlock(rtm);
+
+	trace_contention_end(rwb, ret);
 	return ret;
 }
 
@@ -247,11 +251,13 @@ static int __sched rwbase_write_lock(struct rwbase_rt *rwb,
 		goto out_unlock;
 
 	rwbase_set_and_save_current_state(state);
+	trace_contention_begin(rwb, LCB_F_RT | LCB_F_WRITE);
 	for (;;) {
 		/* Optimized out for rwlocks */
 		if (rwbase_signal_pending_state(state, current)) {
 			rwbase_restore_current_state();
 			__rwbase_write_unlock(rwb, 0, flags);
+			trace_contention_end(rwb, -EINTR);
 			return -EINTR;
 		}
 
@@ -265,6 +271,7 @@ static int __sched rwbase_write_lock(struct rwbase_rt *rwb,
 		set_current_state(state);
 	}
 	rwbase_restore_current_state();
+	trace_contention_end(rwb, 0);
 
 out_unlock:
 	raw_spin_unlock_irqrestore(&rtm->wait_lock, flags);