[bpf-next,1/2] selftests/bpf: Move bench specific metrics into union of structs

Commit Message

Hou Tao Dec. 21, 2023, 2:15 p.m. UTC

From: Hou Tao <[e-mail]>

Various benchmarks define its specific metrics in bench_res. This not
only bloats the size of bench_res, but also make the code that tries to
reuse the space hard to follow.

So move benchmark specific metrics into stand-alone structs and pack
these structs into a union to reduce the size of bench_res.

Signed-off-by: Hou Tao <[e-mail]>
---
 tools/testing/selftests/bpf/bench.c               |  9 +++++----
 tools/testing/selftests/bpf/bench.h               | 15 ++++++++++++---
 .../testing/selftests/bpf/benchs/bench_htab_mem.c | 10 +++++-----
 .../benchs/bench_local_storage_rcu_tasks_trace.c  | 10 +++++-----
 4 files changed, 27 insertions(+), 17 deletions(-)

Comments

Song Liu Jan. 8, 2024, 8:51 p.m. UTC | #1

On Thu, Dec 21, 2023 at 6:14 AM Hou Tao <[e-mail]> wrote:
>
> From: Hou Tao <[e-mail]>
>
> Various benchmarks define its specific metrics in bench_res. This not
> only bloats the size of bench_res, but also make the code that tries to
> reuse the space hard to follow.
>
> So move benchmark specific metrics into stand-alone structs and pack
> these structs into a union to reduce the size of bench_res.
>
> Signed-off-by: Hou Tao <[e-mail]>

Acked-by: Song Liu <[e-mail]>

Patch

diff --git a/tools/testing/selftests/bpf/bench.c b/tools/testing/selftests/bpf/bench.c
index 73ce11b0547d..4832cd4b1c3d 100644
--- a/tools/testing/selftests/bpf/bench.c
+++ b/tools/testing/selftests/bpf/bench.c
@@ -88,9 +88,10 @@  grace_period_latency_basic_stats(struct bench_res res[], int res_cnt, struct bas
 	memset(gp_stat, 0, sizeof(struct basic_stats));
 
 	for (i = 0; i < res_cnt; i++)
-		gp_stat->mean += res[i].gp_ns / 1000.0 / (double)res[i].gp_ct / (0.0 + res_cnt);
+		gp_stat->mean += res[i].rcu.gp_ns / 1000.0 / (double)res[i].rcu.gp_ct /
+				 (0.0 + res_cnt);
 
-#define IT_MEAN_DIFF (res[i].gp_ns / 1000.0 / (double)res[i].gp_ct - gp_stat->mean)
+#define IT_MEAN_DIFF (res[i].rcu.gp_ns / 1000.0 / (double)res[i].rcu.gp_ct - gp_stat->mean)
 	if (res_cnt > 1) {
 		for (i = 0; i < res_cnt; i++)
 			gp_stat->stddev += (IT_MEAN_DIFF * IT_MEAN_DIFF) / (res_cnt - 1.0);
@@ -106,9 +107,9 @@  grace_period_ticks_basic_stats(struct bench_res res[], int res_cnt, struct basic
 
 	memset(gp_stat, 0, sizeof(struct basic_stats));
 	for (i = 0; i < res_cnt; i++)
-		gp_stat->mean += res[i].stime / (double)res[i].gp_ct / (0.0 + res_cnt);
+		gp_stat->mean += res[i].rcu.stime / (double)res[i].rcu.gp_ct / (0.0 + res_cnt);
 
-#define IT_MEAN_DIFF (res[i].stime / (double)res[i].gp_ct - gp_stat->mean)
+#define IT_MEAN_DIFF (res[i].rcu.stime / (double)res[i].rcu.gp_ct - gp_stat->mean)
 	if (res_cnt > 1) {
 		for (i = 0; i < res_cnt; i++)
 			gp_stat->stddev += (IT_MEAN_DIFF * IT_MEAN_DIFF) / (res_cnt - 1.0);
diff --git a/tools/testing/selftests/bpf/bench.h b/tools/testing/selftests/bpf/bench.h
index 68180d8f8558..a6fcf111221f 100644
--- a/tools/testing/selftests/bpf/bench.h
+++ b/tools/testing/selftests/bpf/bench.h
@@ -42,9 +42,18 @@  struct bench_res {
 	long drops;
 	long false_hits;
 	long important_hits;
-	unsigned long gp_ns;
-	unsigned long gp_ct;
-	unsigned int stime;
+
+	/* benchmark specific metrics */
+	union {
+		struct {
+			unsigned long bytes;
+		} htab;
+		struct {
+			unsigned long gp_ns;
+			unsigned long gp_ct;
+			unsigned int stime;
+		} rcu;
+	};
 };
 
 struct bench {
diff --git a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c
index 9146d3f414d2..2f37826332ed 100644
--- a/tools/testing/selftests/bpf/benchs/bench_htab_mem.c
+++ b/tools/testing/selftests/bpf/benchs/bench_htab_mem.c
@@ -293,7 +293,7 @@  static void htab_mem_read_mem_cgrp_file(const char *name, unsigned long *value)
 static void htab_mem_measure(struct bench_res *res)
 {
 	res->hits = atomic_swap(&ctx.skel->bss->op_cnt, 0) / env.producer_cnt;
-	htab_mem_read_mem_cgrp_file("memory.current", &res->gp_ct);
+	htab_mem_read_mem_cgrp_file("memory.current", &res->htab.bytes);
 }
 
 static void htab_mem_report_progress(int iter, struct bench_res *res, long delta_ns)
@@ -301,7 +301,7 @@  static void htab_mem_report_progress(int iter, struct bench_res *res, long delta
 	double loop, mem;
 
 	loop = res->hits / 1000.0 / (delta_ns / 1000000000.0);
-	mem = res->gp_ct / 1048576.0;
+	mem = res->htab.bytes / 1048576.0;
 	printf("Iter %3d (%7.3lfus): ", iter, (delta_ns - 1000000000) / 1000.0);
 	printf("per-prod-op %7.2lfk/s, memory usage %7.2lfMiB\n", loop, mem);
 }
@@ -315,15 +315,15 @@  static void htab_mem_report_final(struct bench_res res[], int res_cnt)
 
 	for (i = 0; i < res_cnt; i++) {
 		loop_mean += res[i].hits / 1000.0 / (0.0 + res_cnt);
-		mem_mean += res[i].gp_ct / 1048576.0 / (0.0 + res_cnt);
+		mem_mean += res[i].htab.bytes / 1048576.0 / (0.0 + res_cnt);
 	}
 	if (res_cnt > 1)  {
 		for (i = 0; i < res_cnt; i++) {
 			loop_stddev += (loop_mean - res[i].hits / 1000.0) *
 				       (loop_mean - res[i].hits / 1000.0) /
 				       (res_cnt - 1.0);
-			mem_stddev += (mem_mean - res[i].gp_ct / 1048576.0) *
-				      (mem_mean - res[i].gp_ct / 1048576.0) /
+			mem_stddev += (mem_mean - res[i].htab.bytes / 1048576.0) *
+				      (mem_mean - res[i].htab.bytes / 1048576.0) /
 				      (res_cnt - 1.0);
 		}
 		loop_stddev = sqrt(loop_stddev);
diff --git a/tools/testing/selftests/bpf/benchs/bench_local_storage_rcu_tasks_trace.c b/tools/testing/selftests/bpf/benchs/bench_local_storage_rcu_tasks_trace.c
index edf0b00418c1..4842f4f2bbea 100644
--- a/tools/testing/selftests/bpf/benchs/bench_local_storage_rcu_tasks_trace.c
+++ b/tools/testing/selftests/bpf/benchs/bench_local_storage_rcu_tasks_trace.c
@@ -190,10 +190,10 @@  static void measure(struct bench_res *res)
 {
 	long ticks;
 
-	res->gp_ct = atomic_swap(&ctx.skel->bss->gp_hits, 0);
-	res->gp_ns = atomic_swap(&ctx.skel->bss->gp_times, 0);
+	res->rcu.gp_ct = atomic_swap(&ctx.skel->bss->gp_hits, 0);
+	res->rcu.gp_ns = atomic_swap(&ctx.skel->bss->gp_times, 0);
 	ticks = kthread_pid_ticks();
-	res->stime = ticks - ctx.prev_kthread_stime;
+	res->rcu.stime = ticks - ctx.prev_kthread_stime;
 	ctx.prev_kthread_stime = ticks;
 }
 
@@ -216,9 +216,9 @@  static void report_progress(int iter, struct bench_res *res, long delta_ns)
 		return;
 
 	printf("Iter %d\t avg tasks_trace grace period latency\t%lf ns\n",
-	       iter, res->gp_ns / (double)res->gp_ct);
+	       iter, res->rcu.gp_ns / (double)res->rcu.gp_ct);
 	printf("Iter %d\t avg ticks per tasks_trace grace period\t%lf\n",
-	       iter, res->stime / (double)res->gp_ct);
+	       iter, res->rcu.stime / (double)res->rcu.gp_ct);
 }
 
 static void report_final(struct bench_res res[], int res_cnt)