Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: prevent recursion
  tracing, doc: update mmiotrace documentation
  x86, mmiotrace: fix buffer overrun detection
  function tracing: fix wrong position computing of stack_trace

diff --git a/Documentation/tracers/mmiotrace.txt b/Documentation/tracers/mmiotrace.txt
index 5bbbe2096223f69bc1f0d7007f6d07a3385e4fd4..cde23b4a12a19a9306464ec1296cb4fee19eb9c0 100644 (file)
--- a/Documentation/tracers/mmiotrace.txt
+++ b/Documentation/tracers/mmiotrace.txt
@@ -37,7 +37,7 @@ $ echo mmiotrace > /debug/tracing/current_tracer
 $ cat /debug/tracing/trace_pipe > mydump.txt &
 Start X or whatever.
 $ echo "X is up" > /debug/tracing/trace_marker
-$ echo none > /debug/tracing/current_tracer
+$ echo nop > /debug/tracing/current_tracer
 Check for lost events.
 
 
@@ -66,7 +66,7 @@ which action. It is recommended to place descriptive markers about what you
 do.
 
 Shut down mmiotrace (requires root privileges):
-$ echo none > /debug/tracing/current_tracer
+$ echo nop > /debug/tracing/current_tracer
 The 'cat' process exits. If it does not, kill it by issuing 'fg' command and
 pressing ctrl+c.
 
@@ -81,7 +81,9 @@ are:
 $ cat /debug/tracing/trace_entries
 gives you a number. Approximately double this number and write it back, for
 instance:
+$ echo 0 > /debug/tracing/tracing_enabled
 $ echo 128000 > /debug/tracing/trace_entries
+$ echo 1 > /debug/tracing/tracing_enabled
 Then start again from the top.
 
 If you are doing a trace for a driver project, e.g. Nouveau, you should also

diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index f780e9552f913e5b9674a218b148f27364e82723..668bbb5ef2bd154dc8084fe4480bfd251e484f41 100644 (file)
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1215,7 +1215,7 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
 
  out:
        if (resched)
-               preempt_enable_notrace();
+               preempt_enable_no_resched_notrace();
        else
                preempt_enable_notrace();
        return NULL;

diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c
index f28484618ff0de99b0c9d5062f23fe8eec25070a..e62cbf78eab6d6a6270a2a5c97f4ffc7ac443525 100644 (file)
--- a/kernel/trace/trace_mmiotrace.c
+++ b/kernel/trace/trace_mmiotrace.c
@@ -18,12 +18,14 @@ struct header_iter {
 
 static struct trace_array *mmio_trace_array;
 static bool overrun_detected;
+static unsigned long prev_overruns;
 
 static void mmio_reset_data(struct trace_array *tr)
 {
        int cpu;
 
        overrun_detected = false;
+       prev_overruns = 0;
        tr->time_start = ftrace_now(tr->cpu);
 
        for_each_online_cpu(cpu)
@@ -128,16 +130,12 @@ static void mmio_close(struct trace_iterator *iter)
 
 static unsigned long count_overruns(struct trace_iterator *iter)
 {
-       int cpu;
        unsigned long cnt = 0;
-/* FIXME: */
-#if 0
-       for_each_online_cpu(cpu) {
-               cnt += iter->overrun[cpu];
-               iter->overrun[cpu] = 0;
-       }
-#endif
-       (void)cpu;
+       unsigned long over = ring_buffer_overruns(iter->tr->buffer);
+
+       if (over > prev_overruns)
+               cnt = over - prev_overruns;
+       prev_overruns = over;
        return cnt;
 }
 

diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c
index be682b62fe586285c77c36d7e7c6d6beb929541f..3bdb44bde4b7e5fa4af698c467f0c64b704e7699 100644 (file)
--- a/kernel/trace/trace_stack.c
+++ b/kernel/trace/trace_stack.c
@@ -184,11 +184,16 @@ static struct file_operations stack_max_size_fops = {
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-       long i = (long)m->private;
+       long i;
 
        (*pos)++;
 
-       i++;
+       if (v == SEQ_START_TOKEN)
+               i = 0;
+       else {
+               i = *(long *)v;
+               i++;
+       }
 
        if (i >= max_stack_trace.nr_entries ||
            stack_dump_trace[i] == ULONG_MAX)
@@ -201,12 +206,15 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
 
 static void *t_start(struct seq_file *m, loff_t *pos)
 {
-       void *t = &m->private;
+       void *t = SEQ_START_TOKEN;
        loff_t l = 0;
 
        local_irq_disable();
        __raw_spin_lock(&max_stack_lock);
 
+       if (*pos == 0)
+               return SEQ_START_TOKEN;
+
        for (; t && l < *pos; t = t_next(m, t, &l))
                ;
 
@@ -235,10 +243,10 @@ static int trace_lookup_stack(struct seq_file *m, long i)
 
 static int t_show(struct seq_file *m, void *v)
 {
-       long i = *(long *)v;
+       long i;
        int size;
 
-       if (i < 0) {
+       if (v == SEQ_START_TOKEN) {
                seq_printf(m, "        Depth   Size      Location"
                           "    (%d entries)\n"
                           "        -----   ----      --------\n",
@@ -246,6 +254,8 @@ static int t_show(struct seq_file *m, void *v)
                return 0;
        }
 
+       i = *(long *)v;
+
        if (i >= max_stack_trace.nr_entries ||
            stack_dump_trace[i] == ULONG_MAX)
                return 0;
@@ -275,10 +285,6 @@ static int stack_trace_open(struct inode *inode, struct file *file)
        int ret;
 
        ret = seq_open(file, &stack_trace_seq_ops);
-       if (!ret) {
-               struct seq_file *m = file->private_data;
-               m->private = (void *)-1;
-       }
 
        return ret;
 }