linux-kernel - [PATCH 1/3] perf sched timehist: Mark schedule function in callchains

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Date:   Thu, 24 Nov 2016 10:11:12 +0900
From:   Namhyung Kim <namhyung@...nel.org>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     Ingo Molnar <mingo@...nel.org>,
        Peter Zijlstra <a.p.zijlstra@...llo.nl>,
        Jiri Olsa <jolsa@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        David Ahern <dsahern@...il.com>,
        Stephane Eranian <eranian@...gle.com>,
        Andi Kleen <andi@...stfloor.org>
Subject: [PATCH 1/3] perf sched timehist: Mark schedule function in callchains

The sched_switch event always captured from the scheduler function.  So
it'd be great omit them from the callchain.  This patch marks the
functions to be omitted by later patch.

Cc: David Ahern <dsahern@...il.com>
Signed-off-by: Namhyung Kim <namhyung@...nel.org>
---
 tools/perf/builtin-sched.c | 21 +++++++++++++++++++++
 tools/perf/util/symbol.h   |  1 +
 2 files changed, 22 insertions(+)

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 829468defa07..cd14189d3943 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1965,7 +1965,28 @@ static bool is_idle_sample(struct perf_sched *sched,
 
 		return false;
 	}
+
 	callchain_cursor_commit(cursor);
+
+	while (true) {
+		struct callchain_cursor_node *node;
+		struct symbol *sym;
+
+		node = callchain_cursor_current(cursor);
+		if (node == NULL)
+			break;
+
+		sym = node->sym;
+		if (sym && sym->name) {
+			if (!strcmp(sym->name, "schedule") ||
+			    !strcmp(sym->name, "__schedule") ||
+			    !strcmp(sym->name, "preempt_schedule"))
+				sym->ignore = 1;
+		}
+
+		callchain_cursor_advance(cursor);
+	}
+
 	return false;
 }
 
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index dec7e2d44885..1bcbefc0c325 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -58,6 +58,7 @@ struct symbol {
 	u16		namelen;
 	u8		binding;
 	u8		idle:1;
+	u8		ignore:1;
 	u8		arch_sym;
 	char		name[0];
 };
-- 
2.10.0