perf hists: Add struct hists pointer to struct hist_entry

Adding pointer back to the parent struct hists for struct hists_entry.

This will be useful in future for any hist_entry's data computation,
that depends on total data of its parent hists.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1349354994-17853-2-git-send-email-namhyung@kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/hist.c

@@ -325,6 +325,7 @@ struct hist_entry *__hists__add_branch_entry(struct hists *self,
 		.parent = sym_parent,
 		.filtered = symbol__parent_filter(sym_parent),
 		.branch_info = bi,
+		.hists	= self,
 	};
 
 	return add_hist_entry(self, &entry, al, period);
@@ -346,6 +347,7 @@ struct hist_entry *__hists__add_entry(struct hists *self,
 		.period	= period,
 		.parent = sym_parent,
 		.filtered = symbol__parent_filter(sym_parent),
+		.hists	= self,
 	};
 
 	return add_hist_entry(self, &entry, al, period);

tools/perf/util/sort.h

@@ -79,6 +79,7 @@ struct hist_entry {
 		struct rb_root	  sorted_chain;
 	};
 	struct branch_info	*branch_info;
+	struct hists		*hists;
 	struct callchain_root	callchain[0];
 };