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| author | Slava Pestov <slavapestov@google.com> | 2011-07-16 01:23:58 +0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2012-11-01 00:45:27 +0400 |
| commit | 884bfe89a462fcc85c8abd96171519cf2fe70929 (patch) | |
| tree | be61b3c6ee4d75198af22f5cdadc3b289b207bda /kernel/trace/trace.c | |
| parent | f43c738bfa8608424610e4fc1aef4d4644e2ce11 (diff) | |
| download | linux-884bfe89a462fcc85c8abd96171519cf2fe70929.tar.xz | |
ring-buffer: Add a 'dropped events' counter
The existing 'overrun' counter is incremented when the ring
buffer wraps around, with overflow on (the default). We wanted
a way to count requests lost from the buffer filling up with
overflow off, too. I decided to add a new counter instead
of retro-fitting the existing one because it seems like a
different statistic to count conceptually, and also because
of how the code was structured.
Link: http://lkml.kernel.org/r/1310765038-26399-1-git-send-email-slavapestov@google.com
Signed-off-by: Slava Pestov <slavapestov@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f6928edacd6d..36c213fbfce7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4385,6 +4385,9 @@ tracing_stats_read(struct file *filp, char __user *ubuf, usec_rem = do_div(t, USEC_PER_SEC); trace_seq_printf(s, "now ts: %5llu.%06lu\n", t, usec_rem); + cnt = ring_buffer_dropped_events_cpu(tr->buffer, cpu); + trace_seq_printf(s, "dropped events: %ld\n", cnt); + count = simple_read_from_buffer(ubuf, count, ppos, s->buffer, s->len); kfree(s); |