perf annotate browser: Initial loop detection
Simple algorithm, just look for the next backward jump that points to
before the cursor.
Then draw an arrow connecting the jump to its target.
Do this as you move the cursor, entering/exiting possible loops.
Ex (graph chars replaced to avoid mail encoding woes):
avc_has_perm_flags
0.00 | nopl 0x0(%rax)
5.36 |+-> 68: mov (%rax),%rax
5.15 || test %rax,%rax
0.00 || v je 130
2.96 || 74: cmp -0x20(%rax),%ebx
47.38 || lea -0x20(%rax),%rcx
0.28 || ^ jne 68
3.16 || cmp -0x18(%rax),%dx
0.00 |+------^ jne 68
4.92 | cmp 0x4(%rcx),%r13d
0.00 | v jne 68
1.15 | test %rcx,%rcx
0.00 | v je 130
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-5gairf6or7dazlx3ocxwvftm@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 973ff74..32ac116 100644
--- a/tools/perf/ui/browser.c
+++ b/tools/perf/ui/browser.c
@@ -600,6 +600,45 @@
SLsmg_set_char_set(0);
}
+void __ui_browser__line_arrow_up(struct ui_browser *browser, unsigned int column,
+ u64 start, u64 end, int start_width)
+{
+ unsigned int row, end_row;
+
+ SLsmg_set_char_set(1);
+
+ if (start < browser->top_idx + browser->height) {
+ row = start - browser->top_idx;
+ ui_browser__gotorc(browser, row, column);
+ SLsmg_write_char(SLSMG_LLCORN_CHAR);
+ ui_browser__gotorc(browser, row, column + 1);
+ SLsmg_draw_hline(start_width);
+
+ if (row-- == 0)
+ goto out;
+ } else
+ row = browser->height - 1;
+
+ if (end > browser->top_idx)
+ end_row = end - browser->top_idx;
+ else
+ end_row = 0;
+
+ ui_browser__gotorc(browser, end_row, column);
+ SLsmg_draw_vline(row - end_row + 1);
+
+ ui_browser__gotorc(browser, end_row, column);
+ if (end >= browser->top_idx) {
+ SLsmg_write_char(SLSMG_ULCORN_CHAR);
+ ui_browser__gotorc(browser, end_row, column + 1);
+ SLsmg_write_char(SLSMG_HLINE_CHAR);
+ ui_browser__gotorc(browser, end_row, column + 2);
+ SLsmg_write_char(SLSMG_RARROW_CHAR);
+ }
+out:
+ SLsmg_set_char_set(0);
+}
+
void ui_browser__init(void)
{
int i = 0;