ftrace: pipe fixes

Some fixes for better output with the trace pipe.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 70f94fa92c105f2c47951f89b9ac5c6e61067aed..c56fc5e6013324a9f485300dcfe52be0a4f2974e 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -770,11 +770,6 @@ trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data,
 
        array = page_address(page);
 
-       /* Still possible to catch up to the tail */
-       if (iter->next_idx[cpu] && array == data->trace_tail &&
-           iter->next_page_idx[cpu] == data->trace_tail_idx)
-               return NULL;
-
        WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE);
        return &array[iter->next_page_idx[cpu]];
 }
@@ -1921,7 +1916,6 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
        struct trace_iterator *iter = filp->private_data;
        struct trace_array_cpu *data;
        static cpumask_t mask;
-       struct trace_entry *entry;
        static int start;
        unsigned long flags;
        int read = 0;
@@ -2013,10 +2007,15 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
                cpu_set(cpu, mask);
        }
 
-       while ((entry = find_next_entry_inc(iter)) != NULL) {
+       while (find_next_entry_inc(iter) != NULL) {
+               int len = iter->seq.len;
+
                ret = print_trace_line(iter);
-               if (!ret)
+               if (!ret) {
+                       /* don't print partial lines */
+                       iter->seq.len = len;
                        break;
+               }
 
                trace_consume(iter);