Re: [PATCH 1/3] tracing/function-graph-tracer: introduce__notrace_funcgraph to filter special functions
From: Ingo Molnar
Date: Mon Dec 08 2008 - 10:50:40 EST
* Frédéric Weisbecker <fweisbec@xxxxxxxxx> wrote:
> 2008/12/8 Ingo Molnar <mingo@xxxxxxx>:
> >
> > * Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote:
> >
> >> Impact: trace more functions
> >>
> >> When the function graph tracer is configured, three more files are not
> >> traced to prevent only four functions to be traced. And this impacts
> >> the normal function tracer too.
> >>
> >> arch/x86/kernel/process_64/32.c:
> >>
> >> I had crashes when I let this file traced. After some debugging, I saw
> >> that the "current" task point was changed inside__swtich_to(), ie:
> >> "write_pda(pcurrent, next_p);" inside process_64.c Since the tracer
> >> store the original return address of the function inside current, we
> >> had crashes. Only __switch_to() has to be traced.
> >>
> >> kernel/module.c and kernel/extable.c:
> >>
> >> Because of a function used internally by the function graph tracer:
> >> __kernel_text_address()
> >>
> >> To let the other functions inside these files to be traced, this patch
> >> introduces the __notrace_funcgraph function prefix which is __notrace
> >> if function graph tracer is configured and nothing if not.
> >>
> >> Signed-off-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
> >
> > applied to tip/tracing/function-graph-tracer, thanks Frederic!
>
> Thanks!
>
> > [ one small request: would it be possible to include the diffstat in the
> > patches you send? If you use git-diff then it's the --patch-with-stat
> > option. ]
>
>
> Ok. BTW. I wanted to give a try on linux-next to test the last ftrace
> stuffs, but the auto-ftrace-next branch seems too much old. Are the
> auto branches updated every week or something like this...?
yes - but there's a few pending regressions right now delaying the
reintegration.
Ingo
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