Messages in this thread | | | Date | Wed, 27 Mar 2013 13:56:45 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCH v7 11/18] perf tools: add mem access sampling core support |
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Em Wed, Mar 27, 2013 at 03:48:15PM +0100, Stephane Eranian escreveu: > 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.
BTW, I fixed up the patches (kernel and user parts) and have them in perf/mem at:
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux
Hope to push it to Ingo today/tomorrow, after some more testing, thanks Jiri for reviewing it.
Stephane, if you could give it a try again to see that the fixups I did (documented in the commit logs, just before my Signed-off-by) are ok, that would be good.
- Arnaldo
> > > > > and that would need the cpumode guessing for DATA ptr, because > > cpumode value is deduced from cs register > > > > jirka
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