perf top: Fix number of samples displayed

In recent versions of perf top, pressing the 'e' key to change the
number of displayed samples had no effect.

The number of samples was still dictated by the size of the terminal
(stdio mode). That was quite annoying because typically only the first
dozen samples really matter.

This patch fixes this.

Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120130105037.GA5160@quad
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index e8b033c074f98d43fd778722a0d718b202c94eab..d869b214ada27365bc7979d73a6f00a478d595ef 100644 (file)
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -88,8 +88,6 @@ void get_term_dimensions(struct winsize *ws)
 
 static void perf_top__update_print_entries(struct perf_top *top)
 {
-       top->print_entries = top->winsize.ws_row;
-
        if (top->print_entries > 9)
                top->print_entries -= 9;
 }
@@ -99,6 +97,13 @@ static void perf_top__sig_winch(int sig __used, siginfo_t *info __used, void *ar
        struct perf_top *top = arg;
 
        get_term_dimensions(&top->winsize);
+       if (!top->print_entries
+           || (top->print_entries+4) > top->winsize.ws_row) {
+               top->print_entries = top->winsize.ws_row;
+       } else {
+               top->print_entries += 4;
+               top->winsize.ws_row = top->print_entries;
+       }
        perf_top__update_print_entries(top);
 }
 
@@ -452,8 +457,10 @@ static void perf_top__handle_keypress(struct perf_top *top, int c)
                                };
                                perf_top__sig_winch(SIGWINCH, NULL, top);
                                sigaction(SIGWINCH, &act, NULL);
-                       } else
+                       } else {
+                               perf_top__sig_winch(SIGWINCH, NULL, top);
                                signal(SIGWINCH, SIG_DFL);
+                       }
                        break;
                case 'E':
                        if (top->evlist->nr_entries > 1) {