On Mon, May 11, 2015 at 9:36 AM, Peter Zijlstra <[email protected]> wrote: > On Mon, May 11, 2015 at 09:32:33AM -0700, Stephane Eranian wrote: >> >> 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)? > > That's FREEZE_LBRS_ON_PMI, I was referring to FREEZE_PERFMON_ON_PMI, > which we've not used so far. > Ah, yes that one was not used so far. I don't quite remember why. I think with PEBS, you don't need it or it should be off or something like this.
> I think Andi tried using it before, but there's some issues with it on > v3, but v4 should have fixed all that. > I was referring to a LBR issue on v3 (HSW) and call stack mode. > Andi can you perhaps explain what the problem with FREEZE_PERFMON_ON_PMI > on v3 was again? > Andi, Is that what I am alluding to above? >> 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. > > We could pull that out in a shared function of course, if possible. Good. -- 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/
