From: Steven Rostedt <rostedt@goodmis.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH] ftrace: Handle TRACE_BPUTS in print_graph_comment
Date: Thu, 1 Sep 2016 12:20:56 -0400 [thread overview]
Message-ID: <20160901122056.7aa075ad@gandalf.local.home> (raw)
In-Reply-To: <20160901024354.13720-1-namhyung@kernel.org>
On Thu, 1 Sep 2016 11:43:54 +0900
Namhyung Kim <namhyung@kernel.org> wrote:
> It missed to handle TRACE_BPUTS so messages recorded by trace_bputs()
> will be shown with symbol info unnecessarily.
>
> You can see it with the trace_printk sample code:
>
> # cd /sys/kernel/tracing/
> # echo sys_sync > set_graph_function
> # echo 1 > options/sym-offset
> # echo function_graph > current_tracer
>
> Note that the sys_sync filter was there to prevent recording other
> functions and the sym-offset option was needed since the first message
> was called from a module init function so kallsyms doesn't have the
> symbol and omitted in the output.
>
> # cd ~/build/kernel
> # insmod samples/trace_printk/trace-printk.ko
>
> # cd -
> # head trace
>
> Before:
>
> # tracer: function_graph
> #
> # CPU DURATION FUNCTION CALLS
> # | | | | | | |
> 1) | /* 0xffffffffa0002000: This is a static string that will use trace_bputs */
> 1) | /* This is a dynamic string that will use trace_puts */
> 1) | /* trace_printk_irq_work+0x5/0x7b [trace_printk]: (irq) This is a static string that will use trace_bputs */
> 1) | /* (irq) This is a dynamic string that will use trace_puts */
> 1) | /* (irq) This is a static string that will use trace_bprintk() */
> 1) | /* (irq) This is a dynamic string that will use trace_printk */
>
> After:
>
> # tracer: function_graph
> #
> # CPU DURATION FUNCTION CALLS
> # | | | | | | |
> 1) | /* This is a static string that will use trace_bputs */
> 1) | /* This is a dynamic string that will use trace_puts */
> 1) | /* (irq) This is a static string that will use trace_bputs */
> 1) | /* (irq) This is a dynamic string that will use trace_puts */
> 1) | /* (irq) This is a static string that will use trace_bprintk() */
> 1) | /* (irq) This is a dynamic string that will use trace_printk */
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
Applied, thanks Namhyung!
-- Steve
prev parent reply other threads:[~2016-09-01 16:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-01 2:43 Namhyung Kim
2016-09-01 16:20 ` Steven Rostedt [this message]
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