tracing: add lockdep tracepoints for lock acquire/release

Augment the traces with lock names when lockdep is available:

 1)               |  down_read_trylock() {
 1)               |    _spin_lock_irqsave() {
 1)               |      /* lock_acquire: &sem->wait_lock */
 1)   4.201 us    |    }
 1)               |    _spin_unlock_irqrestore() {
 1)               |      /* lock_release: &sem->wait_lock */
 1)   3.523 us    |    }
 1)               |  /* lock_acquire: try read &mm->mmap_sem */
 1) + 13.386 us   |  }
 1)   1.635 us    |  find_vma();
 1)               |  handle_mm_fault() {
 1)               |    __do_fault() {
 1)               |      filemap_fault() {
 1)               |        find_lock_page() {
 1)               |          find_get_page() {
 1)               |            /* lock_acquire: read rcu_read_lock */
 1)               |            /* lock_release: rcu_read_lock */
 1)   5.697 us    |          }
 1)   8.158 us    |        }
 1) + 11.079 us   |      }
 1)               |      _spin_lock() {
 1)               |        /* lock_acquire: __pte_lockptr(page) */
 1)   3.949 us    |      }
 1)   1.460 us    |      page_add_file_rmap();
 1)               |      _spin_unlock() {
 1)               |        /* lock_release: __pte_lockptr(page) */
 1)   3.115 us    |      }
 1)               |      unlock_page() {
 1)   1.421 us    |        page_waitqueue();
 1)   1.220 us    |        __wake_up_bit();
 1)   6.519 us    |      }
 1) + 34.328 us   |    }
 1) + 37.452 us   |  }
 1)               |  up_read() {
 1)               |  /* lock_release: &mm->mmap_sem */
 1)               |    _spin_lock_irqsave() {
 1)               |      /* lock_acquire: &sem->wait_lock */
 1)   3.865 us    |    }
 1)               |    _spin_unlock_irqrestore() {
 1)               |      /* lock_release: &sem->wait_lock */
 1)   8.562 us    |    }
 1) + 17.370 us   |  }

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: =?ISO-8859-1?Q?T=F6r=F6k?= Edwin <edwintorok@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1236166375.5330.7209.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 8 insertions, 6 deletions

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 12539f72f4a5..c8abbb0c8397 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -623,7 +623,7 @@ static unsigned map_pid_to_cmdline[PID_MAX_DEFAULT+1];
 static unsigned map_cmdline_to_pid[SAVED_CMDLINES];
 static char saved_cmdlines[SAVED_CMDLINES][TASK_COMM_LEN];
 static int cmdline_idx;
-static DEFINE_SPINLOCK(trace_cmdline_lock);
+static raw_spinlock_t trace_cmdline_lock = __RAW_SPIN_LOCK_UNLOCKED;
 
 /* temporary disable recording */
 static atomic_t trace_record_cmdline_disabled __read_mostly;
@@ -735,7 +735,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
          * nor do we want to disable interrupts,
          * so if we miss here, then better luck next time.
          */
-        if (!spin_trylock(&trace_cmdline_lock))
+        if (!__raw_spin_trylock(&trace_cmdline_lock))
                 return;
 
         idx = map_pid_to_cmdline[tsk->pid];
@@ -753,7 +753,7 @@ static void trace_save_cmdline(struct task_struct *tsk)
 
         memcpy(&saved_cmdlines[idx], tsk->comm, TASK_COMM_LEN);
 
-        spin_unlock(&trace_cmdline_lock);
+        __raw_spin_unlock(&trace_cmdline_lock);
 }
 
 char *trace_find_cmdline(int pid)
@@ -3751,7 +3751,7 @@ static __init int tracer_init_debugfs(void)
 
 int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
 {
-        static DEFINE_SPINLOCK(trace_buf_lock);
+        static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED;
         static char trace_buf[TRACE_BUF_SIZE];
 
         struct ring_buffer_event *event;
@@ -3773,7 +3773,8 @@ int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
                 goto out;
 
         pause_graph_tracing();
-        spin_lock_irqsave(&trace_buf_lock, irq_flags);
+        raw_local_irq_save(irq_flags);
+        __raw_spin_lock(&trace_buf_lock);
         len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);
 
         len = min(len, TRACE_BUF_SIZE-1);
@@ -3792,7 +3793,8 @@ int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args)
         ring_buffer_unlock_commit(tr->buffer, event);
 
  out_unlock:
-        spin_unlock_irqrestore(&trace_buf_lock, irq_flags);
+        __raw_spin_unlock(&trace_buf_lock);
+        raw_local_irq_restore(irq_flags);
         unpause_graph_tracing();
  out:
         preempt_enable_notrace();