Re: [PATCH] ftrace: Handle TRACE_BPUTS in print_graph_comment

From: Steven Rostedt
Date: Thu Sep 01 2016 - 12:21:06 EST


On Thu, 1 Sep 2016 11:43:54 +0900
Namhyung Kim <namhyung@xxxxxxxxxx> 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@xxxxxxxxxx>
> ---

Applied, thanks Namhyung!

-- Steve