From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755478AbaDTPMK (ORCPT ); Sun, 20 Apr 2014 11:12:10 -0400 Received: from mx.insigma.com.cn ([115.236.48.170]:45771 "EHLO WX-Ex2010Edge01.insigma.com.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755461AbaDTPLp (ORCPT ); Sun, 20 Apr 2014 11:11:45 -0400 From: Jiaxing Wang To: Steven Rostedt , Frederic Weisbecker , Ingo Molnar CC: , Jiaxing Wang Subject: [PATCH 1/2] tracing/trace_stack:Skip 4 instead of 3 when using ftrace_ops_list_func Date: Sun, 20 Apr 2014 23:10:43 +0800 Message-ID: <1398006644-5935-2-git-send-email-wangjiaxing@insigma.com.cn> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1398006644-5935-1-git-send-email-wangjiaxing@insigma.com.cn> References: <1398006644-5935-1-git-send-email-wangjiaxing@insigma.com.cn> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [120.40.72.205] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When using ftrace_ops_list_func, we should skip 4 instead of 3, to avoid ftrace_call+0x5/0xb appearing in the stack trace: Depth Size Location (110 entries) ----- ---- -------- 0) 2956 0 update_curr+0xe/0x1e0 1) 2956 68 ftrace_call+0x5/0xb 2) 2888 92 enqueue_entity+0x53/0xe80 3) 2796 80 enqueue_task_fair+0x47/0x7e0 4) 2716 28 enqueue_task+0x45/0x70 5) 2688 12 activate_task+0x22/0x30 Add a function using_ftrace_ops_list_func() to test for this while keeping ftrace_ops_list_func to remain static. Signed-off-by: Jiaxing Wang --- kernel/trace/ftrace.c | 5 +++++ kernel/trace/trace.h | 1 + kernel/trace/trace_stack.c | 8 ++++++-- 3 files changed, 12 insertions(+), 2 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 1fd4b94..e7e7302 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -373,6 +373,11 @@ static void update_ftrace_function(void) ftrace_trace_function = func; } +int using_ftrace_ops_list_func(void) +{ + return ftrace_trace_function == ftrace_ops_list_func; +} + static void add_ftrace_ops(struct ftrace_ops **list, struct ftrace_ops *ops) { ops->next = *list; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index ffc314b..920c0a5 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -822,6 +822,7 @@ extern int ftrace_is_dead(void); int ftrace_create_function_files(struct trace_array *tr, struct dentry *parent); void ftrace_destroy_function_files(struct trace_array *tr); +int using_ftrace_ops_list_func(void); #else static inline int ftrace_trace_task(struct task_struct *task) { diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 21b320e..5aa9a5b 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -85,8 +85,12 @@ check_stack(unsigned long ip, unsigned long *stack) max_stack_size = this_size; - max_stack_trace.nr_entries = 0; - max_stack_trace.skip = 3; + max_stack_trace.nr_entries = 0; + + if (using_ftrace_ops_list_func()) + max_stack_trace.skip = 4; + else + max_stack_trace.skip = 3; save_stack_trace(&max_stack_trace); -- 1.8.3.2