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    SubjectRe: [PATCH] ftrace: powerpc: remove startup functions from tracing

    On Fri, 17 Oct 2008, Benjamin Herrenschmidt wrote:

    > On Thu, 2008-10-16 at 20:48 -0400, Steven Rostedt wrote:
    > >
    > > The early init code in PowerPC is not mapped to their final locations
    > > and all jumps and memory references must be done with relative jumps
    > > and accesses.
    > >
    > > The lib files in the powerpc directory are called in early boot, and
    > > since mcount will perform direct access to memory, the lib files need
    > > not be traced.
    > This is annoying though, because that means things like memcpy,
    > copy_to_from_user etc... can't be traced. On the other hand a lot
    > of that is asm and already doesn't call mcount.

    Yeah, I know. I was going to pick and choose which files in there should
    be converted, but then I saw that they were mostly asm, and it seemed to
    be better safe than sorry.

    Sure, we could probably bring it down a bit. But I'm a bit paranoid it may
    cause someone else not to boot because of something else being called at
    early boot up.

    But don't worry. When we get MCOUNT_RECORD ported to PPC this no longer
    becomes an issue, and we can simply do a
    "ifndef CONFIG_FTRACE_MCOUNT_RECORD" around the -pg removal in the
    Makefile. (or what ever the Makefile syntax is for config options)

    -- Steve

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