On Wed, Nov 16, 2022 at 10:47:04PM +0000, Edgecombe, Rick P wrote: > On Wed, 2022-11-16 at 14:33 -0800, Luis Chamberlain wrote: > > More in lines with what I was hoping for. Can something just do > > the parallelization for you in one shot? Can bench alone do it for > > you? > > Is there no interest to have soemthing which generically showcases > > multithreading / hammering a system with tons of eBPF JITs? It may > > prove useful. > > > > And also, it begs the question, what if you had another iTLB generic > > benchmark or genearl memory pressure workload running *as* you run > > the > > above? I as, as it was my understanding that one of the issues was > > the > > long term slowdown caused by the directmap fragmentation without > > bpf_prog_pack, and so such an application should crawl to its knees > > over time, and there should be numbers you could show to prove that > > too, before and after. > > We did have some benchmarks that showed if your direct map was totally > fragmented (started from boot at 4k page size) what the regression was: > > > https://lore.kernel.org/linux-mm/213b4567-46ce-f116-9cdf-bbd0c884eb3c@xxxxxxxxxxxxxxx/ Oh yes that is a good example of effort, but I'm suggesting taking for instance will-it-scale and run it in tandem with bpg prog pack and measure on *both* iTLB differences, before / after, *and* doing this again after a period of expected deterioation of the direct map fragmentation (say after non-bpf-prog-pack shows high direct map fragmetnation). This is the sort of thing which easily go into a commit log. Luis
