Messages in this thread | | | Date | Wed, 27 Mar 2013 15:48:15 +0100 | Subject | Re: [PATCH v7 11/18] perf tools: add mem access sampling core support | From | Stephane Eranian <> |
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On Wed, Mar 27, 2013 at 3:34 PM, Jiri Olsa <jolsa@redhat.com> wrote: > > On Wed, Mar 27, 2013 at 03:20:14PM +0100, Peter Zijlstra wrote: > > On Wed, 2013-03-27 at 15:14 +0100, Jiri Olsa wrote: > > > we have correct cpumode for sample->ip, but I think it's the > > > PEBS->dla (sample->addr) where we need to guess.. right? > > > > kernel mode very much fakes the cpumode/segment stuff for PEBS. PEBS > > assumes you're running in a linear/flat mode. > > > > say we hit the sample when kernel accesses the user data, we will endup > with IP in kernel space and DATA ptr in user space.. in theory ;-) > Yes, this is possible. So I think we could probably leaverage ip__resolve_ams() and pass the extra parameter for MAP_VARIABLE vs. MAP_FUNCTION.
> > and that would need the cpumode guessing for DATA ptr, because > cpumode value is deduced from cs register > > jirka
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