Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755370Ab3DYGuu (ORCPT ); Thu, 25 Apr 2013 02:50:50 -0400 Received: from LGEMRELSE6Q.lge.com ([156.147.1.121]:57373 "EHLO LGEMRELSE6Q.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751120Ab3DYGut (ORCPT ); Thu, 25 Apr 2013 02:50:49 -0400 X-AuditID: 9c930179-b7b5bae0000069d1-b0-5178d2459ba7 From: Namhyung Kim To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Paul Mackerras , Ingo Molnar , Namhyung Kim , LKML , Steven Rostedt , Frederic Weisbecker , David Ahern , Stephane Eranian Subject: Re: [PATCH 12/14] perf ftrace: Use pager for displaying result References: <1366705872-12132-1-git-send-email-namhyung@kernel.org> <1366705872-12132-13-git-send-email-namhyung@kernel.org> <20130424141724.GH971@krava.brq.redhat.com> Date: Thu, 25 Apr 2013 15:50:45 +0900 In-Reply-To: <20130424141724.GH971@krava.brq.redhat.com> (Jiri Olsa's message of "Wed, 24 Apr 2013 16:17:24 +0200") Message-ID: <877gjr9k8q.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1794 Lines: 57 On Wed, 24 Apr 2013 16:17:24 +0200, Jiri Olsa wrote: > On Tue, Apr 23, 2013 at 05:31:10PM +0900, Namhyung Kim wrote: >> From: Namhyung Kim >> >> It's convenient to use pager when seeing many lines of result. >> > for some reason I'm able to get any output for 'live' command only > when using --no-pager option. I dont get any data for: > > # ./perf ftrace live ls > > not even ls output > > But sometime I dont even get ftrace output for: > > # ./perf --no-pager ftrace live ls > > just ls output > > > I wonder there's some race with reading trace_pipe file, > I haven't checked deeply yet.. It seems go_pipe in perf_evlist__prepare_workload() was closed due to the pager process, so the workload ended up blocking indefinitely. I guess other subcommands were not affected by this since record doesn't use a pager, and show and report don't have a workload. Does the patch below fix it? diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 95f9a7fa3e04..3f3a684193e0 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -1486,12 +1486,12 @@ __cmd_ftrace_live(struct perf_ftrace *ftrace, int argc, const char **argv) if (!argc && perf_target__none(&ftrace->target)) usage_with_options(live_usage, live_options); + setup_pager(); + ret = ftrace_setup(ftrace, argc, argv); if (ret < 0) return ret; - setup_pager(); - ret = do_ftrace_live(ftrace); ftrace_teardown(ftrace); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/