On Mon, Jul 08, 2019 at 09:23:19AM +0800, Wei Wang wrote: > This patch enables the LBR related features in Arch v4 in advance, > though the current vPMU only has v2 support. Other arch v4 related > support will be enabled later in another series. > > Arch v4 supports streamlined Freeze_LBR_on_PMI. According to the SDM, > the LBR_FRZ bit is set to global status when debugctl.freeze_lbr_on_pmi > has been set and a PMI is generated. The CTR_FRZ bit is set when > debugctl.freeze_perfmon_on_pmi is set and a PMI is generated. (that's still a misnomer; it is: freeze_perfmon_on_overflow) Why? Who uses that v4 crud? It's broken. It looses events between overflow and PMI.
