linux-kernel - [PATCH v2 2/6] perf symbols: Avoid unnecessary symbol loading when dso list is specified

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Date:	Wed, 24 Mar 2010 16:40:15 -0300
From:	Arnaldo Carvalho de Melo <acme@...radead.org>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	linux-kernel@...r.kernel.org,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Frédéric Weisbecker <fweisbec@...il.com>,
	Mike Galbraith <efault@....de>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>
Subject: [PATCH v2 2/6] perf symbols: Avoid unnecessary symbol loading when dso list is specified

From: Arnaldo Carvalho de Melo <acme@...hat.com>

We were performing the full thread__find_addr_location operation, i.e.
resolving to a map/dso _and_ loading its symbols when we can optimize it
by first calling thread__find_addr_map to find just the map/dso, check
if it is one that we are interested in (passed via --dsos/-d in 'perf
annotate', 'perf report', etc) and if not avoid loading the symtab.

Nice speedup when we know which DSO we're interested in.

Cc: Frédéric Weisbecker <fweisbec@...il.com>
Cc: Mike Galbraith <efault@....de>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Paul Mackerras <paulus@...ba.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/event.c |   38 +++++++++++++++++++++++---------------
 1 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 705ec63..c2808ad 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -513,24 +513,32 @@ int event__preprocess_sample(const event_t *self, struct perf_session *session,
 
 	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
 
-	thread__find_addr_location(thread, session, cpumode, MAP__FUNCTION,
-				   self->ip.ip, al, filter);
+	thread__find_addr_map(thread, session, cpumode, MAP__FUNCTION,
+			      self->ip.ip, al);
 	dump_printf(" ...... dso: %s\n",
 		    al->map ? al->map->dso->long_name :
 			al->level == 'H' ? "[hypervisor]" : "<not found>");
-	/*
-	 * We have to do this here as we may have a dso with no symbol hit that
-	 * has a name longer than the ones with symbols sampled.
-	 */
-	if (al->map && !sort_dso.elide && !al->map->dso->slen_calculated)
-		dso__calc_col_width(al->map->dso);
-
-	if (symbol_conf.dso_list &&
-	    (!al->map || !al->map->dso ||
-	     !(strlist__has_entry(symbol_conf.dso_list, al->map->dso->short_name) ||
-	       (al->map->dso->short_name != al->map->dso->long_name &&
-		strlist__has_entry(symbol_conf.dso_list, al->map->dso->long_name)))))
-		goto out_filtered;
+	al->sym = NULL;
+
+	if (al->map) {
+		if (symbol_conf.dso_list &&
+		    (!al->map || !al->map->dso ||
+		     !(strlist__has_entry(symbol_conf.dso_list,
+					  al->map->dso->short_name) ||
+		       (al->map->dso->short_name != al->map->dso->long_name &&
+			strlist__has_entry(symbol_conf.dso_list,
+					   al->map->dso->long_name)))))
+			goto out_filtered;
+		/*
+		 * We have to do this here as we may have a dso with no symbol
+		 * hit that has a name longer than the ones with symbols
+		 * sampled.
+		 */
+		if (!sort_dso.elide && !al->map->dso->slen_calculated)
+			dso__calc_col_width(al->map->dso);
+
+		al->sym = map__find_symbol(al->map, al->addr, filter);
+	}
 
 	if (symbol_conf.sym_list && al->sym &&
 	    !strlist__has_entry(symbol_conf.sym_list, al->sym->name))
-- 
1.6.2.5

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