On Mon, Nov 7, 2022 at 4:13 PM Edgecombe, Rick P <rick.p.edgecombe@xxxxxxxxx> wrote: > > On Mon, 2022-11-07 at 15:39 -0800, Luis Chamberlain wrote: > > On Mon, Nov 07, 2022 at 03:13:59PM -0800, Song Liu wrote: > > > The benchmark used here is identical on our web service, which runs > > > on > > > many many servers, so it represents the workload that we care a > > > lot. > > > Unfortunately, it is not possible to run it out of our data > > > centers. > > > > I am not asking for that, I am asking for you to pick any similar > > benchark which can run in paralellel which may yield similar results. > > > > > We can build some artificial workloads and probably get much higher > > > performance improvements. But these workload may not represent real > > > world use cases. > > > > You can very likely use some existing benchmark. > > > > The direct map fragmentation stuff doesn't require much effort, as > > was demonstrated by Aaron, you can easily do that or more by > > running all selftests or just the test_bpf. This I buy. > > > > I'm not buying the iTLB gains as I can't even reproduce them myself > > for > > eBPF JIT, but I tested against iTLB when using eBPF JIT, perhaps you > > mean iTLB gains for other memory intensive applications running in > > tandem? > > Song, didn't you find that there wasn't (or in the noise) iTLB gains? > What is this about visible performance drop from iTLB misses? > > IIRC there was a test done where progpack mapped things at 4k, but in > 2MB chunks, so it would re-use pages like the 2MB mapped version. And > it didn't see much improvement over the 2MB mapped version. Did I > remember that wrong? There is still a small gain (~0.2%) for this benchmark. Thanks, Song > > > > > And none of your patches mentions the gains of this effort helping > > with the long term advantage of centralizing the semantics for > > permissions on memory. > > Another good point. Although this brings up that this interface > "execmem" does just handle one type of permission.
