On Wed, Jul 2, 2014 at 2:27 PM, Peter Zijlstra <pet...@infradead.org> wrote: > On Wed, Jul 02, 2014 at 01:08:30PM +0200, Stephane Eranian wrote: >> On Wed, Jul 2, 2014 at 12:57 PM, Peter Zijlstra <pet...@infradead.org> wrote: >> > On Mon, Jun 30, 2014 at 04:50:47PM +0800, Yan, Zheng wrote: >> >> event->attr.branch_sample_type is non-zero no matter branch stack >> >> is enabled explicitly or is enabled implicitly. we can use it to >> >> replace intel_pmu_needs_lbr_smpl(). This avoids duplicating code >> >> that implicitly enables the LBR. >> > >> > How so? I grep'ed for a minute but could not find what you're referring >> > to. >> >> If !(attr->sample_type & PERF_SAMPLE_BRANCH_STACK), then >> event->attr.branch_type = 0. If the sample_type is set, then branch_type >> is necessarily non-zero. > > Does not compute.. and that appears to contradict whatever Yan Zheng > tries to say. He says that we have branch_type != 0 for PEBS events, and > I couldn't find where that lived.
He is probably talking about precise=2 for non HSW PMU. But it is true, you need to look at x86_pmu_hw_config() *br_type = PERF_SAMPLE_BRANCH_ANY; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/