From: Joanne Koong <joannekoong@fb.com>
Date: Wed, 27 Oct 2021 16:45:04 -0700
Subject: bpf/benchs: Add benchmarks for comparing hashmap lookups w/ vs. w/out
bloom filter
Patch-mainline: v5.16-rc1
Git-commit: f44bc543a079c2ebc534cbfabd6fbfcfc2b09f72
References: jsc#PED-1377
This patch adds benchmark tests for comparing the performance of hashmap
lookups without the bloom filter vs. hashmap lookups with the bloom filter.
Checking the bloom filter first for whether the element exists should
overall enable a higher throughput for hashmap lookups, since if the
element does not exist in the bloom filter, we can avoid a costly lookup in
the hashmap.
On average, using 5 hash functions in the bloom filter tended to perform
the best across the widest range of different entry sizes. The benchmark
results using 5 hash functions (running on 8 threads on a machine with one
numa node, and taking the average of 3 runs) were roughly as follows:
value_size = 4 bytes -
10k entries: 30% faster
50k entries: 40% faster
100k entries: 40% faster
500k entres: 70% faster
1 million entries: 90% faster
5 million entries: 140% faster
value_size = 8 bytes -
10k entries: 30% faster
50k entries: 40% faster
100k entries: 50% faster
500k entres: 80% faster
1 million entries: 100% faster
5 million entries: 150% faster
value_size = 16 bytes -
10k entries: 20% faster
50k entries: 30% faster
100k entries: 35% faster
500k entres: 65% faster
1 million entries: 85% faster
5 million entries: 110% faster
value_size = 40 bytes -
10k entries: 5% faster
50k entries: 15% faster
100k entries: 20% faster
500k entres: 65% faster
1 million entries: 75% faster
5 million entries: 120% faster
Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-6-joannekoong@fb.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
tools/testing/selftests/bpf/bench.c | 23 +++-
tools/testing/selftests/bpf/benchs/bench_bloom_filter_map.c | 57 ++++++++++
tools/testing/selftests/bpf/benchs/run_bench_bloom_filter_map.sh | 17 ++
tools/testing/selftests/bpf/benchs/run_common.sh | 12 ++
4 files changed, 104 insertions(+), 5 deletions(-)
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -92,20 +92,22 @@ void hits_drops_report_progress(int iter
printf("Iter %3d (%7.3lfus): ",
iter, (delta_ns - 1000000000) / 1000.0);
- printf("hits %8.3lfM/s (%7.3lfM/prod), drops %8.3lfM/s\n",
- hits_per_sec, hits_per_prod, drops_per_sec);
+ printf("hits %8.3lfM/s (%7.3lfM/prod), drops %8.3lfM/s, total operations %8.3lfM/s\n",
+ hits_per_sec, hits_per_prod, drops_per_sec, hits_per_sec + drops_per_sec);
}
void hits_drops_report_final(struct bench_res res[], int res_cnt)
{
int i;
- double hits_mean = 0.0, drops_mean = 0.0;
- double hits_stddev = 0.0, drops_stddev = 0.0;
+ double hits_mean = 0.0, drops_mean = 0.0, total_ops_mean = 0.0;
+ double hits_stddev = 0.0, drops_stddev = 0.0, total_ops_stddev = 0.0;
+ double total_ops;
for (i = 0; i < res_cnt; i++) {
hits_mean += res[i].hits / 1000000.0 / (0.0 + res_cnt);
drops_mean += res[i].drops / 1000000.0 / (0.0 + res_cnt);
}
+ total_ops_mean = hits_mean + drops_mean;
if (res_cnt > 1) {
for (i = 0; i < res_cnt; i++) {
@@ -115,14 +117,21 @@ void hits_drops_report_final(struct benc
drops_stddev += (drops_mean - res[i].drops / 1000000.0) *
(drops_mean - res[i].drops / 1000000.0) /
(res_cnt - 1.0);
+ total_ops = res[i].hits + res[i].drops;
+ total_ops_stddev += (total_ops_mean - total_ops / 1000000.0) *
+ (total_ops_mean - total_ops / 1000000.0) /
+ (res_cnt - 1.0);
}
hits_stddev = sqrt(hits_stddev);
drops_stddev = sqrt(drops_stddev);
+ total_ops_stddev = sqrt(total_ops_stddev);
}
printf("Summary: hits %8.3lf \u00B1 %5.3lfM/s (%7.3lfM/prod), ",
hits_mean, hits_stddev, hits_mean / env.producer_cnt);
- printf("drops %8.3lf \u00B1 %5.3lfM/s\n",
+ printf("drops %8.3lf \u00B1 %5.3lfM/s, ",
drops_mean, drops_stddev);
+ printf("total operations %8.3lf \u00B1 %5.3lfM/s\n",
+ total_ops_mean, total_ops_stddev);
}
const char *argp_program_version = "benchmark";
@@ -357,6 +366,8 @@ extern const struct bench bench_pb_custo
extern const struct bench bench_bloom_lookup;
extern const struct bench bench_bloom_update;
extern const struct bench bench_bloom_false_positive;
+extern const struct bench bench_hashmap_without_bloom;
+extern const struct bench bench_hashmap_with_bloom;
static const struct bench *benchs[] = {
&bench_count_global,
@@ -381,6 +392,8 @@ static const struct bench *benchs[] = {
&bench_bloom_lookup,
&bench_bloom_update,
&bench_bloom_false_positive,
+ &bench_hashmap_without_bloom,
+ &bench_hashmap_with_bloom,
};
static void setup_benchmark()
--- a/tools/testing/selftests/bpf/benchs/bench_bloom_filter_map.c
+++ b/tools/testing/selftests/bpf/benchs/bench_bloom_filter_map.c
@@ -346,6 +346,41 @@ static void false_positive_setup(void)
}
}
+static void hashmap_with_bloom_setup(void)
+{
+ struct bpf_link *link;
+
+ ctx.use_hashmap = true;
+ ctx.hashmap_use_bloom = true;
+
+ ctx.skel = setup_skeleton();
+
+ populate_maps();
+
+ link = bpf_program__attach(ctx.skel->progs.bloom_hashmap_lookup);
+ if (!link) {
+ fprintf(stderr, "failed to attach program!\n");
+ exit(1);
+ }
+}
+
+static void hashmap_no_bloom_setup(void)
+{
+ struct bpf_link *link;
+
+ ctx.use_hashmap = true;
+
+ ctx.skel = setup_skeleton();
+
+ populate_maps();
+
+ link = bpf_program__attach(ctx.skel->progs.bloom_hashmap_lookup);
+ if (!link) {
+ fprintf(stderr, "failed to attach program!\n");
+ exit(1);
+ }
+}
+
static void measure(struct bench_res *res)
{
unsigned long total_hits = 0, total_drops = 0, total_false_hits = 0;
@@ -418,3 +453,25 @@ const struct bench bench_bloom_false_pos
.report_progress = false_hits_report_progress,
.report_final = false_hits_report_final,
};
+
+const struct bench bench_hashmap_without_bloom = {
+ .name = "hashmap-without-bloom",
+ .validate = validate,
+ .setup = hashmap_no_bloom_setup,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
+
+const struct bench bench_hashmap_with_bloom = {
+ .name = "hashmap-with-bloom",
+ .validate = validate,
+ .setup = hashmap_with_bloom_setup,
+ .producer_thread = producer,
+ .consumer_thread = consumer,
+ .measure = measure,
+ .report_progress = hits_drops_report_progress,
+ .report_final = hits_drops_report_final,
+};
--- a/tools/testing/selftests/bpf/benchs/run_bench_bloom_filter_map.sh
+++ b/tools/testing/selftests/bpf/benchs/run_bench_bloom_filter_map.sh
@@ -26,3 +26,20 @@ subtitle "value_size: $v bytes, # thread
done
done
done
+
+header "Hashmap without bloom filter vs. hashmap with bloom filter (throughput, 8 threads)"
+for v in 2 4 8 16 40; do
+for h in {1..10}; do
+subtitle "value_size: $v, # hashes: $h"
+ for e in 10000 50000 75000 100000 250000 500000 750000 1000000 2500000 5000000; do
+ printf "%'d entries -\n" $e
+ printf "\t"
+ summarize_total "Hashmap without bloom filter: " \
+ "$($RUN_BENCH --nr_hash_funcs $h --nr_entries $e --value_size $v -p 8 hashmap-without-bloom)"
+ printf "\t"
+ summarize_total "Hashmap with bloom filter: " \
+ "$($RUN_BENCH --nr_hash_funcs $h --nr_entries $e --value_size $v -p 8 hashmap-with-bloom)"
+ done
+ printf "\n"
+done
+done
--- a/tools/testing/selftests/bpf/benchs/run_common.sh
+++ b/tools/testing/selftests/bpf/benchs/run_common.sh
@@ -33,6 +33,11 @@ function percentage()
echo "$*" | sed -E "s/.*Percentage\s=\s+([0-9]+\.[0-9]+).*/\1/"
}
+function total()
+{
+ echo "$*" | sed -E "s/.*total operations\s+([0-9]+\.[0-9]+ ± [0-9]+\.[0-9]+M\/s).*/\1/"
+}
+
function summarize()
{
bench="$1"
@@ -46,3 +51,10 @@ function summarize_percentage()
summary=$(echo $2 | tail -n1)
printf "%-20s %s%%\n" "$bench" "$(percentage $summary)"
}
+
+function summarize_total()
+{
+ bench="$1"
+ summary=$(echo $2 | tail -n1)
+ printf "%-20s %s\n" "$bench" "$(total $summary)"
+}