On Mon, Apr 25, 2016 at 10:24:31PM -0300, Arnaldo Carvalho de Melo wrote: > Em Mon, Apr 25, 2016 at 10:03:58PM -0300, Arnaldo Carvalho de Melo escreveu: > > I now need to continue investigation why this doesn't seem to work from > > tracepoints... > > Bummer, the changeset (at the end of this message) hasn't any > explanation, is this really impossible? I.e. LBR callstacks from > tracepoints? Even if we set perf_event_attr.exclude_callchain_kernel?
Could maybe be done, but its tricky to implement as the LBR is managed by the hardware PMU and tracepoints are a software PMU, so we need to then somehow frob with cross-pmu resources, in a very arch specific way. And programmability of the hardware PMU will then depend on events outside of it. All rather icky.
