From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Frederic Weisbecker <frederic@kernel.org>,
Joel Fernandes <joel@joelfernandes.org>,
Andy Lutomirski <luto@kernel.org>,
Mark Rutland <mark.rutland@arm.com>
Subject: [RFC][PATCH 10/14] function_graph: Have profiler use new helper ftrace_graph_get_ret_stack()
Date: Wed, 21 Nov 2018 20:27:18 -0500 [thread overview]
Message-ID: <20181122012803.976067055@goodmis.org> (raw)
In-Reply-To: 20181122012708.491151844@goodmis.org
From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
The ret_stack processing is going to change, and that is going
to break anything that is accessing the ret_stack directly. One user is the
function graph profiler. By using the ftrace_graph_get_ret_stack() helper
function, the profiler can access the ret_stack entry without relying on the
implementation details of the stack itself.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
include/linux/ftrace.h | 3 +++
kernel/trace/fgraph.c | 11 +++++++++++
kernel/trace/ftrace.c | 21 +++++++++++----------
3 files changed, 25 insertions(+), 10 deletions(-)
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 5544df21a886..36a0fd1316dd 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -792,6 +792,9 @@ extern int
function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp);
+struct ftrace_ret_stack *
+ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
+
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp);
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index c7d612897e33..9b85638ecded 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -233,6 +233,17 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer)
return ret;
}
+struct ftrace_ret_stack *
+ftrace_graph_get_ret_stack(struct task_struct *task, int idx)
+{
+ idx = current->curr_ret_stack - idx;
+
+ if (idx >= 0 && idx <= task->curr_ret_stack)
+ return ¤t->ret_stack[idx];
+
+ return NULL;
+}
+
/**
* ftrace_graph_ret_addr - convert a potentially modified stack return address
* to its original value
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d057dde081e7..05568ad4e590 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -792,7 +792,7 @@ void ftrace_graph_graph_time_control(bool enable)
static int profile_graph_entry(struct ftrace_graph_ent *trace)
{
- int index = current->curr_ret_stack;
+ struct ftrace_ret_stack *ret_stack;
function_profile_call(trace->func, 0, NULL, NULL);
@@ -800,14 +800,16 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace)
if (!current->ret_stack)
return 0;
- if (index >= 0 && index < FTRACE_RETFUNC_DEPTH)
- current->ret_stack[index].subtime = 0;
+ ret_stack = ftrace_graph_get_ret_stack(current, 0);
+ if (ret_stack)
+ ret_stack->subtime = 0;
return 1;
}
static void profile_graph_return(struct ftrace_graph_ret *trace)
{
+ struct ftrace_ret_stack *ret_stack;
struct ftrace_profile_stat *stat;
unsigned long long calltime;
struct ftrace_profile *rec;
@@ -825,16 +827,15 @@ static void profile_graph_return(struct ftrace_graph_ret *trace)
calltime = trace->rettime - trace->calltime;
if (!fgraph_graph_time) {
- int index;
-
- index = current->curr_ret_stack;
/* Append this call time to the parent time to subtract */
- if (index)
- current->ret_stack[index - 1].subtime += calltime;
+ ret_stack = ftrace_graph_get_ret_stack(current, 1);
+ if (ret_stack)
+ ret_stack->subtime += calltime;
- if (current->ret_stack[index].subtime < calltime)
- calltime -= current->ret_stack[index].subtime;
+ ret_stack = ftrace_graph_get_ret_stack(current, 0);
+ if (ret_stack && ret_stack->subtime < calltime)
+ calltime -= ret_stack->subtime;
else
calltime = 0;
}
--
2.19.1
next prev parent reply other threads:[~2018-11-22 1:29 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-22 1:27 [RFC][PATCH 00/14] function_graph: Rewrite to allow multiple users Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 01/14] fgraph: Create a fgraph.c file to store function graph infrastructure Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 02/14] fgraph: Have set_graph_notrace only affect function_graph tracer Steven Rostedt
2018-11-23 0:01 ` Namhyung Kim
2018-11-23 17:37 ` Steven Rostedt
2018-11-24 5:49 ` Namhyung Kim
2018-11-24 18:41 ` Steven Rostedt
2018-11-26 4:54 ` Namhyung Kim
2018-11-22 1:27 ` [RFC][PATCH 03/14] arm64: function_graph: Remove use of FTRACE_NOTRACE_DEPTH Steven Rostedt
2018-11-27 19:31 ` Will Deacon
2018-11-27 19:50 ` Steven Rostedt
2018-12-05 21:50 ` [PATCH 03/14 v2] " Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 04/14] function_graph: Remove the " Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 05/14] ftrace: Create new ftrace-internal.h header Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 06/14] fgraph: Move function graph specific code into fgraph.c Steven Rostedt
2018-11-23 6:11 ` Joel Fernandes
2018-11-23 17:58 ` Steven Rostedt
2018-11-23 18:11 ` Steven Rostedt
2018-11-23 22:13 ` Joel Fernandes
2018-11-26 7:25 ` Masami Hiramatsu
2018-11-22 1:27 ` [RFC][PATCH 07/14] fgraph: Add new fgraph_ops structure to enable function graph hooks Steven Rostedt
2018-11-23 2:59 ` Joel Fernandes
2018-11-23 18:25 ` Steven Rostedt
2018-11-26 11:30 ` Masami Hiramatsu
2018-11-26 21:06 ` Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 08/14] function_graph: Remove unused task_curr_ret_stack() Steven Rostedt
2018-11-26 7:40 ` Masami Hiramatsu
2018-11-26 21:26 ` Steven Rostedt
2018-11-26 10:02 ` Joey Pabalinas
2018-11-26 21:27 ` Steven Rostedt
2018-11-26 21:37 ` Joey Pabalinas
2018-11-22 1:27 ` [RFC][PATCH 09/14] function_graph: Move ftrace_graph_get_addr() to fgraph.c Steven Rostedt
2018-11-23 3:13 ` Joel Fernandes
2018-11-23 19:25 ` Steven Rostedt
2018-11-22 1:27 ` Steven Rostedt [this message]
2018-11-22 1:27 ` [RFC][PATCH 11/14] function_graph: Convert ret_stack to a series of longs Steven Rostedt
2018-11-24 5:31 ` Joel Fernandes
2018-11-26 16:07 ` Masami Hiramatsu
2018-11-26 16:26 ` Steven Rostedt
2018-11-28 1:38 ` Joel Fernandes
2018-11-26 21:31 ` Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 12/14] function_graph: Add an array structure that will allow multiple callbacks Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 13/14] function_graph: Allow multiple users to attach to function graph Steven Rostedt
2018-11-22 1:27 ` [RFC][PATCH 14/14] function_graph: Allow for more than one callback to be registered Steven Rostedt
2018-11-22 10:08 ` [RFC][PATCH 00/14] function_graph: Rewrite to allow multiple users Peter Zijlstra
2018-11-22 12:46 ` Steven Rostedt
2018-11-22 13:42 ` Peter Zijlstra
2018-11-26 9:21 ` Masami Hiramatsu
2018-11-26 16:32 ` Steven Rostedt
2018-11-29 14:29 ` Masami Hiramatsu
2018-11-29 16:46 ` Steven Rostedt
2018-11-30 2:26 ` Masami Hiramatsu
2018-11-30 3:24 ` Steven Rostedt
2018-11-30 14:11 ` Masami Hiramatsu
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