linux-kernel - [PATCH] perf tool: remove an unnecessary function call while process pipe events

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1383297900-3749-1-git-send-email-chenggang.qin@gmail.com>
Date:	Fri,  1 Nov 2013 17:25:00 +0800
From:	Chenggang Qin <chenggang.qin@...il.com>
To:	linux-kernel@...r.kernel.org
Cc:	Chenggang Qin <chenggang.qcg@...bao.com>,
	David Ahern <dsahern@...il.com>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Paul Mackerras <paulus@...ba.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...stprotocols.net>,
	Arjan van de Ven <arjan@...ux.intel.com>,
	Namhyung Kim <namhyung@...il.com>,
	Yanmin Zhang <yanmin.zhang@...el.com>,
	Wu Fengguang <fengguang.wu@...el.com>,
	Mike Galbraith <efault@....de>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH] perf tool: remove an unnecessary function call while process pipe events

From: Chenggang Qin <chenggang.qcg@...bao.com>

perf_session_free_sample_buffers() can be removed from
__perf_session__process_pipe_events(), since the ordered_samples buffer is not
used while samples are read from the pipe.
__perf_session__process_pipe_events() is only used while process the events from
pipe. While the sample are read from pipe, the ordered_samples is forbidden.
Refer to the following code in perf_session__new():
 150         if (tool && tool->ordering_requires_timestamps &&
 151             tool->ordered_samples && !perf_evlist__sample_id_all(self->evlist)) {
 152                 dump_printf("WARNING: No sample_id_all support, falling back to unordered processing\n");
 153                 tool->ordered_samples = false;
 154         }
If pipe is used, perf_evlist__sample_id_all(self->evlist) always return 0. Because
session->evlist is empty util a attr_event is read.

Thanks
Chenggang Qin

Cc: David Ahern <dsahern@...il.com>
Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Paul Mackerras <paulus@...ba.org>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Arnaldo Carvalho de Melo <acme@...stprotocols.net>
Cc: Arjan van de Ven <arjan@...ux.intel.com>
Cc: Namhyung Kim <namhyung@...il.com>
Cc: Yanmin Zhang <yanmin.zhang@...el.com>
Cc: Wu Fengguang <fengguang.wu@...el.com>
Cc: Mike Galbraith <efault@....de>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Chenggang Qin <chenggang.qcg@...bao.com>

---
 tools/perf/util/session.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 568b750..b69c28a 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1251,7 +1251,6 @@ done:
 out_err:
 	free(buf);
 	perf_session__warn_about_errors(self, tool);
-	perf_session_free_sample_buffers(self);
 	return err;
 }
 
-- 
1.7.8.rc2.5.g815b

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/