linux/tools/testing
Hou Tao fd283ab196 selftests/bpf: Add benchmark for bpf memory allocator
The benchmark could be used to compare the performance of hash map
operations and the memory usage between different flavors of bpf memory
allocator (e.g., no bpf ma vs bpf ma vs reuse-after-gp bpf ma). It also
could be used to check the performance improvement or the memory saving
provided by optimization.

The benchmark creates a non-preallocated hash map which uses bpf memory
allocator and shows the operation performance and the memory usage of
the hash map under different use cases:
(1) overwrite
Each CPU overwrites nonoverlapping part of hash map. When each CPU
completes overwriting of 64 elements in hash map, it increases the
op_count.
(2) batch_add_batch_del
Each CPU adds then deletes nonoverlapping part of hash map in batch.
When each CPU adds and deletes 64 elements in hash map, it increases
the op_count twice.
(3) add_del_on_diff_cpu
Each two-CPUs pair adds and deletes nonoverlapping part of map
cooperatively. When each CPU adds or deletes 64 elements in hash map,
it will increase the op_count.

The following is the benchmark results when comparing between different
flavors of bpf memory allocator. These tests are conducted on a KVM guest
with 8 CPUs and 16 GB memory. The command line below is used to do all
the following benchmarks:

  ./bench htab-mem --use-case $name ${OPTS} -w3 -d10 -a -p8

These results show that preallocated hash map has both better performance
and smaller memory footprint.

(1) non-preallocated + no bpf memory allocator (v6.0.19)
use kmalloc() + call_rcu

overwrite            per-prod-op: 11.24 ± 0.07k/s, avg mem: 82.64 ± 26.32MiB, peak mem: 119.18MiB
batch_add_batch_del  per-prod-op: 18.45 ± 0.10k/s, avg mem: 50.47 ± 14.51MiB, peak mem: 94.96MiB
add_del_on_diff_cpu  per-prod-op: 14.50 ± 0.03k/s, avg mem: 4.64 ± 0.73MiB, peak mem: 7.20MiB

(2) preallocated
OPTS=--preallocated

overwrite            per-prod-op: 191.42 ± 0.09k/s, avg mem: 1.24 ± 0.00MiB, peak mem: 1.49MiB
batch_add_batch_del  per-prod-op: 221.83 ± 0.17k/s, avg mem: 1.23 ± 0.00MiB, peak mem: 1.49MiB
add_del_on_diff_cpu  per-prod-op: 39.66 ± 0.31k/s, avg mem: 1.47 ± 0.13MiB, peak mem: 1.75MiB

(3) normal bpf memory allocator

overwrite            per-prod-op: 126.59 ± 0.02k/s, avg mem: 2.26 ± 0.00MiB, peak mem: 2.74MiB
batch_add_batch_del  per-prod-op: 83.37 ± 0.20k/s, avg mem: 2.14 ± 0.17MiB, peak mem: 2.74MiB
add_del_on_diff_cpu  per-prod-op: 21.25 ± 0.24k/s, avg mem: 17.50 ± 3.32MiB, peak mem: 28.87MiB

Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230704025039.938914-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
History 2023-07-05 18:36:19 -07:00
..
crypto/chacha20-s390 tools/testing/crypto: Use vzalloc instead of vmalloc+memset 2022-07-05 14:46:36 +02:00
cxl cxl: Move cxl_await_media_ready() to before capacity info retrieval 2023-05-18 16:43:45 -07:00
fault-injection docs: fault-injection: convert docs to ReST and rename to *.rst 2019-06-14 14:21:07 -06:00
ktest ktest: Restore stty setting at first in dodie 2023-02-20 11:52:27 -05:00
kunit hardening updates for v6.5-rc1 2023-06-27 21:24:18 -07:00
memblock mm, treewide: redefine MAX_ORDER sanely 2023-04-05 19:42:46 -07:00
nvdimm Driver core changes for 6.4-rc1 2023-04-27 11:53:57 -07:00
radix-tree Merge mm-hotfixes-stable into mm-stable to pick up depended-upon changes. 2023-06-23 16:58:19 -07:00
scatterlist tools/testing/scatterlist: add missing defines 2022-01-30 09:56:58 +02:00
selftests selftests/bpf: Add benchmark for bpf memory allocator 2023-07-05 18:36:19 -07:00
vsock vsock/test: update expected return values 2023-04-04 12:46:24 +02:00