On Tue, Jun 2, 2015 at 5:39 PM, Andi Kleen <a...@linux.intel.com> wrote: > On Tue, Jun 02, 2015 at 05:21:27PM -0700, Andy Lutomirski wrote: >> On Tue, Jun 2, 2015 at 4:38 PM, Andi Kleen <a...@linux.intel.com> wrote: >> > On Tue, Jun 02, 2015 at 11:03:26PM +0200, Thomas Gleixner wrote: >> >> >> >> >> >> On Tue, 2 Jun 2015, Andi Kleen wrote: >> >> >> >> > > There's the code in tsc_msr.c. It should be relatively >> >> > > straightforward to extend it to cover everything that intel_pstate >> >> > > supports. >> >> > >> >> > That's a good idea, but we still need an always working fallback when >> >> > the >> >> > model number is not available. So Adrian's patch is needed in any >> >> > case. >> >> >> >> Nonsense. The slow calibration is already a working fallback. >> > >> > Please read Adrian's description again. It's not working when the PIT read >> > is >> > too slow. That is when the new algorithm is needed. >> > >> >> tglx's suggestion was to use slow calibration as a fallback. > > You mean the last fallback we have today? > > That one doesn't work if the PIT read is too slow. > > And Adrian's patch is fixing that.
Then the changelog should say that I think. The current text says "Fast TSC calibration will always fail", which, to me, suggests that either the slow calibration will work or that the changelog message should be changed. --Andy -- 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/
