perf ui browser: Allow specifying message to show when no samples are available to...

The 'perf top' tool will use that to avoid having a initial blank screen
while collecting the minimum number of samples to sort and display.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-89ciceg8cy4442he3t0jzo3f@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/ui/browser.c b/tools/perf/ui/browser.c
index d227d74..c797a85 100644 (file)
--- a/tools/perf/ui/browser.c
+++ b/tools/perf/ui/browser.c
@@ -347,6 +347,8 @@ static int __ui_browser__refresh(struct ui_browser *browser)
        SLsmg_fill_region(browser->y + row + browser->extra_title_lines, browser->x,
                          browser->rows - row, width, ' ');
 
+       if (browser->nr_entries == 0 && browser->no_samples_msg)
+               __ui__info_window(NULL, browser->no_samples_msg, NULL);
        return 0;
 }
 

diff --git a/tools/perf/ui/browser.h b/tools/perf/ui/browser.h
index dc14441..3678eb8 100644 (file)
--- a/tools/perf/ui/browser.h
+++ b/tools/perf/ui/browser.h
@@ -23,6 +23,7 @@ struct ui_browser {
        void          *priv;
        const char    *title;
        char          *helpline;
+       const char    *no_samples_msg;
        void          (*refresh_dimensions)(struct ui_browser *browser);
        unsigned int  (*refresh)(struct ui_browser *browser);
        void          (*write)(struct ui_browser *browser, void *entry, int row);