From: Daniel Xu <dxu@xxxxxxxxx> Date: Tue, 20 Aug 2024 17:29:45 -0700 > Hi Olek, > > On Mon, Aug 19, 2024 at 04:50:52PM GMT, Alexander Lobakin wrote: > [..] >>> Thanks A LOT for doing this benchmarking! >> >> I optimized the code a bit and picked my old patches for bulk NAPI skb >> cache allocation and today I got 4.7 Mpps 🎉 >> IOW, the result of the series (7 patches totally, but 2 are not >> networking-related) is 2.7 -> 4.7 Mpps == 75%! >> >> Daniel, >> >> if you want, you can pick my tree[0], either full or just up to >> >> "bpf: cpumap: switch to napi_skb_cache_get_bulk()" >> >> (13 patches total: 6 for netdev_feature_t and 7 for the cpumap) >> >> and test with your usecases. Would be nice to see some real world >> results, not my synthetic tests :D >> >>> --Jesper >> >> [0] >> https://github.com/alobakin/linux/compare/idpf-libie-new~52...idpf-libie-new/ > > So it turns out keeping the workload in place while I update and reboot > the kernel is a Hard Problem. I'll put in some more effort and see if I > can get one of the workloads to stay still, but it'll be a somewhat > noisy test even if it works. So the following are synthetic tests > (neper) but on a real prod setup as far as container networking and > configuration is concerned. > > I cherry-picked 586be610~1..ca22ac8e9de onto our 6.9-ish branch. Had to > skip some of the flag refactors b/c of conflicts - I didn't know the > code well enough to do fixups. So I had to apply this diff (FWIW not sure > the struct_size() here was right anyhow): > > diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c > index 089d19c62efe..359fbfaa43eb 100644 > --- a/kernel/bpf/cpumap.c > +++ b/kernel/bpf/cpumap.c > @@ -110,7 +110,7 @@ static struct bpf_map *cpu_map_alloc(union bpf_attr *attr) > if (!cmap->cpu_map) > goto free_cmap; > > - dev = bpf_map_area_alloc(struct_size(dev, priv, 0), NUMA_NO_NODE); > + dev = bpf_map_area_alloc(sizeof(*dev), NUMA_NO_NODE); Hmm, it will allocate the same amount of memory. Why do you need this? Are you running these patches on some older kernel which doesn't have a proper flex array at the end of &net_device? > if (!dev) > goto free_cpu_map; > > > ==== Baseline === > ./tcp_rr -c -H $SERVER -p 50,90,99 -T4 -F8 -l30 ./tcp_stream -c -H $SERVER -T8 -F16 -l30 > > Transactions Latency P50 (s) Latency P90 (s) Latency P99 (s) Throughput (Mbit/s) > Run 1 2578189 0.00008831 0.00010623 0.00013439 Run 1 15427.22 > Run 2 2657923 0.00008575 0.00010239 0.00012927 Run 2 15272.12 > Run 3 2700402 0.00008447 0.00010111 0.00013183 Run 3 14871.35 > Run 4 2571739 0.00008575 0.00011519 0.00013823 Run 4 15344.72 > Run 5 2476427 0.00008703 0.00013055 0.00016895 Run 5 15193.2 > Average 2596936 0.000086262 0.000111094 0.000140534 Average 15221.722 > > === cpumap NAPI patches === > Transactions Latency P50 (s) Latency P90 (s) Latency P99 (s) Throughput (Mbit/s) > Run 1 2554598 0.00008703 0.00011263 0.00013055 Run 1 17090.29 > Run 2 2478905 0.00009087 0.00011391 0.00014463 Run 2 16742.27 > Run 3 2418599 0.00009471 0.00011007 0.00014207 Run 3 17555.3 > Run 4 2562463 0.00008959 0.00010367 0.00013055 Run 4 17892.3 > Run 5 2716551 0.00008127 0.00010879 0.00013439 Run 5 17578.32 > Average 2546223.2 0.000088694 0.000109814 0.000136438 Average 17371.696 > Delta -1.95% 2.82% -1.15% -2.91% 14.12% > > > So it looks like the GRO patches work quite well out of the box. It's > curious that tcp_rr transactions go down a bit, though. I don't have any > intuition around that. 14% is quite nice I'd say. Is this first table taken from the cpumap as well or just direct Rx? > > Lemme know if you wanna change some stuff and get a rerun. > > Thanks, > Daniel Thanks, Olek
