perf ui: New hists tree widget
The stock newt checkbox tree widget we were using was not really
suitable for hist entry + callchain browsing.
The problems with it were manifold:
- We needed to traverse the whole hist_entry rb_tree to add each entry +
callchains beforehand.
- No control over the colors used for each row
So a new tree widget, based mostly on slang, was written.
It extends the ui_browser class already used for annotate to allow the
user to fold/unfold branches in the callchains tree, using extra fields
in the symbol_map class that is embedded in hist_entry and
callchain_node instances to store the folding state and when changing
this state calculates the number of rows that are produced when showing
a particular hist_entry instance.
This greatly speeds up browsing as we don't have to upfront touch all
the entries and only calculate callchain related operations when some
callchain branch is actually unfolded.
The memory footprint is also reduced as the data structure is not
duplicated, just some extra fields for controling callchain state and to
simplify the process of seeking thru entries (nr_rows, row_offset) were
added.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/sort.h b/tools/perf/util/sort.h
index 03a1722..46e531d 100644
--- a/tools/perf/util/sort.h
+++ b/tools/perf/util/sort.h
@@ -38,6 +38,12 @@
extern struct sort_entry sort_parent;
extern enum sort_type sort__first_dimension;
+/**
+ * struct hist_entry - histogram entry
+ *
+ * @row_offset - offset from the first callchain expanded to appear on screen
+ * @nr_rows - rows expanded in callchain, recalculated on folding/unfolding
+ */
struct hist_entry {
struct rb_node rb_node;
u64 period;
@@ -50,6 +56,12 @@
u64 ip;
s32 cpu;
u32 nr_events;
+
+ /* XXX These two should move to some tree widget lib */
+ u16 row_offset;
+ u16 nr_rows;
+
+ bool init_have_children;
char level;
u8 filtered;
struct symbol *parent;