On Fri, Jul 03, 2020 at 04:59:49PM -0400, Liang, Kan wrote: > On 7/3/2020 3:50 PM, Peter Zijlstra wrote:
> > If I'm not mistaken, this correctly deals with LBR_FORMAT_INFO, so can't > > we also use the intel_pmu_arch_lbr_read() function for that case? > > But the intel_pmu_arch_lbr_read() doesn't have the optimization > (LBR_NO_INFO) for the LBR_FORMAT_INFO. > https://lkml.kernel.org/r/[email protected] > > To apply the optimization, we need extra codes as below. Right, I saw that, but shouldn't we support that for anything with this format anyway? That is, it's weird and inconsistent to not support PERF_SAMPLE_BRANCH_NO_{CYCLES,FLAGS} for PEBS/ARCH-LBR output. Arguably, we should even support NO_CYCLES for FORMAT_TIME. Yes it's daft, but that's what you get for adding the ABI.
