From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760842AbaGYPhc (ORCPT ); Fri, 25 Jul 2014 11:37:32 -0400 Received: from mail.kernel.org ([198.145.19.201]:34888 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752615AbaGYPh3 (ORCPT ); Fri, 25 Jul 2014 11:37:29 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Adrian Hunter , David Ahern , Frederic Weisbecker , Jiri Olsa , Namhyung Kim , Paul Mackerras , Peter Zijlstra , Stephane Eranian , Arnaldo Carvalho de Melo Subject: [PATCH 02/27] perf tools: Fix jump label always changing during tracing Date: Fri, 25 Jul 2014 12:36:44 -0300 Message-Id: <1406302629-11790-3-git-send-email-acme@kernel.org> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1406302629-11790-1-git-send-email-acme@kernel.org> References: <1406302629-11790-1-git-send-email-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Adrian Hunter Intel PT decoding walks the object code to reconstruct the trace. A jump label change during tracing causes decoding errors. The "Enable close-on-exec flag on perf file descriptor" patch caused there to be always a jump label change. It was found that using a per-cpu context instead of a per-thread context for the probe of the close-on-exec feature, made the problem go away. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1406035081-14301-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/cloexec.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c index c5d05ec17220..6a37be53a5d2 100644 --- a/tools/perf/util/cloexec.c +++ b/tools/perf/util/cloexec.c @@ -1,3 +1,4 @@ +#include #include "util.h" #include "../perf.h" #include "cloexec.h" @@ -14,9 +15,13 @@ static int perf_flag_probe(void) }; int fd; int err; + int cpu = sched_getcpu(); + + if (cpu < 0) + cpu = 0; /* check cloexec flag */ - fd = sys_perf_event_open(&attr, 0, -1, -1, + fd = sys_perf_event_open(&attr, -1, cpu, -1, PERF_FLAG_FD_CLOEXEC); err = errno; @@ -30,7 +35,7 @@ static int perf_flag_probe(void) err, strerror(err)); /* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */ - fd = sys_perf_event_open(&attr, 0, -1, -1, 0); + fd = sys_perf_event_open(&attr, -1, cpu, -1, 0); err = errno; if (WARN_ONCE(fd < 0, -- 1.9.3