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    SubjectRe: [PATCH] Add kernel support for oprofile callgraphs on AVR32
    "Voss, Nikolaus" <> wrote:
    > Hi,
    > > Hmm. This appears to be the third backtracer added to avr32, the first
    > > two being dump_stack() and friends in arch/avr32/kernel/process.c, and
    > > save_stack_trace() in arch/avr32/kernel/stacktrace.c.
    > >
    > > Would be nice if some of this could be consolidated.
    > I considered using one of them, in fact I also have a version with an
    > extended stacktrace.c. But due to the small size of the kernel stacktracer
    > (only a few lines), I found it cleaner to create a separate version. The
    > overall size is smaller and it cannot potentially mess up other things.
    > Cf. e.g. the x86 tracer which is of the generic type, but comparatively big
    > and hard to follow through the places.

    Good point.

    > > > + /* Assume we have frame pointers in user mode process */
    > >
    > > What happens if we don't? I assume it will stop when it detects that
    > > the frame pointer isn't monotonically increasing or when it gets a
    > > fault?
    > Right. This might lead to false information in oprofile, this case is
    > described in the oprofile docs.


    I've applied it to the avr32 tree along with a couple of trivial
    checkpatch fixes. There's one remaining warning:

    WARNING: externs should be avoided in .c files
    #125: FILE: arch/avr32/oprofile/op_model_avr32.c:25:
    +void avr32_backtrace(struct pt_regs * const regs, unsigned int depth);

    total: 0 errors, 1 warnings, 102 lines checked

    We should probably add a header file somewhere, but I'm too lazy to do
    it right now.


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      Last update: 2008-09-03 13:05    [W:0.020 / U:5.424 seconds]
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