[PATCH 49/75] perf top: Move lost events warning to helpline

Arnaldo Carvalho de Melo
2018-12-06T21:29:52Z

From: Jiri Olsa <jolsa@kernel.org>

We can't display the UI box saying that we are slow in the reader
thread. That will make 'perf top' even slower and the user even more
angry ;-)

Move the UI box message from the reader thread to the UI thread and
change it to a helpline, so there's no need to 'press any key'.

Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/n/tip-x4k0iuw7tt6mywsaguq6jfwu@git.kernel.org
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/builtin-top.c | 16 +++++-----------
1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index c02ea537d5a7..9fe835ba0697 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -553,8 +553,6 @@ static void perf_top__sort_new_samples(void *arg)
struct perf_evsel *evsel = t->sym_evsel;
struct hists *hists;

- perf_top__reset_sample_counters(t);
-
if (t->evlist->selected != NULL)
t->sym_evsel = t->evlist->selected;

@@ -571,6 +569,11 @@ static void perf_top__sort_new_samples(void *arg)

hists__collapse_resort(hists, NULL);
perf_evsel__output_resort(evsel, NULL);
+
+ if (t->lost)
+ pr_warning("Too slow to read ring buffer (change period (-c/-F) or limit CPUs (-C)\n");
+
+ perf_top__reset_sample_counters(t);
}

static void *display_thread_tui(void *arg)
@@ -908,10 +911,8 @@ static void perf_top__mmap_read(struct perf_top *top)
{
bool overwrite = top->record_opts.overwrite;
struct perf_evlist *evlist = top->evlist;
- unsigned long long start, end;
int i;

- start = rdclock();
if (overwrite)
perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_DATA_PENDING);

@@ -922,13 +923,6 @@ static void perf_top__mmap_read(struct perf_top *top)
perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_EMPTY);
perf_evlist__toggle_bkw_mmap(evlist, BKW_MMAP_RUNNING);
}
- end = rdclock();
-
- if ((end - start) > (unsigned long long)top->delay_secs * NSEC_PER_SEC)
- ui__warning("Too slow to read ring buffer.\n"
- "Please try increasing the period (-c) or\n"
- "decreasing the freq (-F) or\n"
- "limiting the number of CPUs (-C)\n");
}

/*
--
2.19.2