On Thu, Jan 30, 2020 at 1:19 AM Floris Van Nee <florisvan...@optiver.com> wrote: > I'd say applying just v2-0001 is actually slightly hurtful for single-core > performance. Applying all of them gives a good improvement though. It looks > like the performance improvement is also more noticeable at higher core > counts now.
Many thanks for testing once again! Your tests show that the overall winner is "<v2-0001+2+3>", which is strictly better than all other configurations you tested -- it is at least slightly better than every other configuration at every client count tested. I was particularly pleased to see that "<v2-0001+2+3>" is ~8.6% faster than the master branch with 30 clients! That result greatly exceeded my expectations. I have been able to independently confirm that you really need the first two patches together to see the benefits -- that wasn't clear until recently. The interesting thing now is the role of the "negative infinity test" patch (the 0003-* patch) in all of this. I suspect that it may not be helping us much here. I wonder, could you test the following configurations to settle this question? * <master> with 30 clients (i.e. repeat the test that you reported on most recently) * <v2-0001+2+3> with 30 clients (i.e. repeat the test that you reported got us that nice ~8.6% increase in TPS) * <v2-0001+2> with 30 clients -- a new test, to see if performance is at all helped by the "negative infinity test" patch (the 0003-* patch). It seems like a good idea to repeat the other two tests as part of performing this third test, out of general paranoia. Intel seem to roll out a microcode update for a spectre-like security issue about every other day. Thanks again -- Peter Geoghegan
