On Mon, May 11, 2015 at 9:23 AM, Peter Zijlstra <[email protected]> wrote: > On Sun, May 10, 2015 at 12:22:47PM -0700, Andi Kleen wrote: >> From: Andi Kleen <[email protected]> >> >> With Arch Perfmon v4 the PMU ack unfreezes the LBRs. So we need to do >> the PMU ack after the LBR reading, otherwise the LBRs would be polluted by >> the >> PMI handler. > > Hmm, we should move these last three patches before the SKL enablement > patch no, otherwise things will misbehave -- say a bisection lands in > between. > > /me shuffles patches. > >> This is a minimal change. In principle the ACK could be moved much later. > > Right, so the more complete change would be to use the new and improved > FREEZE_ON_PMI and reenable both the LBRs and the CTRs with the > STATUS_RESET MSR, right? > > Does it make sense to have a new handle_irq() routine for that?
Were we not already using FREEZE_ON_PMI with LBR (except for one erratum on HSW)? It would make sense to me to have an "optimized" and clean handle_irq for the newer PMU. We the caveat that any change to the core of it would now have to be done twice. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
