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    SubjectRe: [Questions] How to run 'perf top' on ARM to profile kernel functions with modules loaded
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    On Thu, 2010-11-11 at 09:17 +0000, Jamie Iles wrote:
    > On Thu, Nov 11, 2010 at 03:52:07PM +0800, Ming Lei wrote:
    > > 2010/11/11 Ming Lei <tom.leiming@gmail.com>:
    > > > Hi,
    > > >
    > > > 'perf top' can't display any functions when modules are loaded on ARM.
    > >
    > > Sorry, should be can't display any kernel functions when modules are loaded
    > > on ARM.
    > I've noticed this myself and I spent a bit of time looking into it last week
    > but didn't get too far. I did wonder if it was something to do with the map
    > fixups after loading the modules. If you look at the raw events after a perf
    > record with 'perf report -D' then the last module has a size that takes it to
    > 0xFFFFFFFF which overlaps with the rest of the kernel symbols.
    >
    > On x86 it looks like the modules are loaded after the kernel image in VM
    > unlike ARM.

    Order shouldn't matter, but that overlap is very likely what kills it.
    That module size is buggy.


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