Re: [tip:perfcounters/core] perf record/report: Add call graph / call chain profiling

Ingo Molnar
2009-06-17T12:25:25Z

* Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:

> > The context IDs would occupy some rare and
> > unlikely-to-be-allocated-soon corner of the address space - say
> > startig at 0x8765432112345000. (and real RIPs would be filtered
> > and nudged just outside that space of a handful IDs.)
>
> Right, that works too, but should we use (u64)-1..-4095 for that?
> We already use that range for things like ERR_PTR() so its very
> unlikely we have something sensible mapped there.

Makes sense. It's also an easier (and more natural) enumeration
method.

Ingo