perf hists browser: Recalculate browser pointers after resort/decay

In browsers that access dynamic underlying data structures, like in the
hists browser and its hist_entry rb_tree, we need to revalidate any
reference to the underlying data structure, because they can have gone
away, decayed.

This fixes a problem where after a while the top entries get behind the
top of the screen, i.e. the top_idx stays at 0, which means it is at the
first entry in the rb_tree when in fact it wasn't because the
browser->top didn't got revalidated after the timer ran and the
underlying data structure got updated.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
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-mhje66qssdko24q67a2lhlho@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tools/perf/util/ui/browser.h b/tools/perf/util/ui/browser.h
index fc63dda1091..d42be43ac0e 100644
--- a/tools/perf/util/ui/browser.h
+++ b/tools/perf/util/ui/browser.h
@@ -41,6 +41,7 @@ int ui_browser__show(struct ui_browser *self, const char *title,
 void ui_browser__hide(struct ui_browser *self);
 int ui_browser__refresh(struct ui_browser *self);
 int ui_browser__run(struct ui_browser *self);
+void ui_browser__update_nr_entries(struct ui_browser *browser, u32 nr_entries);
 
 void ui_browser__rb_tree_seek(struct ui_browser *self, off_t offset, int whence);
 unsigned int ui_browser__rb_tree_refresh(struct ui_browser *self);