On 2024/9/10 19:27, Jesper Dangaard Brouer wrote: ... >> >> The main issue I remembered was that it only support x86:( >> > > Yes, because I've added ASM code for reading TSC counter in a very > precise manor. Given we run many iterations, then I don't think we > need this precise reading. I guess it can simply be replaced with > get_cycles() or get_cycles64(). Then it should work on all archs. Agreed. > > The code already supports wall-clock time via ktime_get() (specifically > ktime_get_real_ts64()). > > >>> >>> My preference here (for the performance part) is to upstream the >>> out-of-tree tests that Jesper (and probably others) are using, rather >>> than adding a new performance test that is not as battle-hardened. >> >> I looked through the out-of-tree tests again, it seems we can take the >> best of them. >> For Jesper' ko: >> It seems we can do prefill as something that pp_fill_ptr_ring() does >> in bench_page_pool_simple.c to avoid the noise from the page allocator. >> >> >> For the ko in this patch: >> It uses NAPI instead of tasklet mimicking the NAPI context, support >> PP_FLAG_DMA_MAP flag testing, and return '-EAGAIN' in module_init() >> to use perf stat for collecting and calculating performance data. >> > My bench don't return minus-number on module load, because I used perf > record, and to see symbols decoded with perf report, I needed the module > to be loaded. > > I started on reading the PMU counters[1] around the bench loop, it works > if enabling PMU counters yourself/manually, but I never finished that work. > > [1] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/include/linux/time_bench.h#L195-L209 > > >> Is there other testcase or better practicing that we can learn from >> Jesper' out of tree ko? >> > > I created a time_bench.c [2] module that other modules [3] can use to > easier reuse the benchmarking code in other modules. > > [2] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/lib/time_bench.c > > [3] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/lib/bench_page_pool_simple.c Will take a look at it, thanks. > > --Jesper
