From ddf37874e2b82849db63f2379edc6b5ba54e2665 Mon Sep 17 00:00:00 2001
From: Andrew Kim <andrew.kim@intel.com>
Date: Wed, 5 Nov 2025 14:37:29 -0800
Subject: [PATCH 3/3] Benchmark code for postgres checksums

Add pg_checksum_bench extension for performance testing of checksum
implementations with AVX2 optimization.

Key features:
- PostgreSQL extension for benchmarking checksum performance
- Tests pg_checksum_block_choose() with runtime AVX2 dispatch
---
 contrib/meson.build                           |  1 +
 contrib/pg_checksum_bench/meson.build         | 23 ++++++++++
 .../pg_checksum_bench--1.0.sql                |  8 ++++
 contrib/pg_checksum_bench/pg_checksum_bench.c | 42 +++++++++++++++++++
 .../pg_checksum_bench.control                 |  4 ++
 .../sql/pg_checksum_bench.sql                 | 17 ++++++++
 6 files changed, 95 insertions(+)
 create mode 100644 contrib/pg_checksum_bench/meson.build
 create mode 100644 contrib/pg_checksum_bench/pg_checksum_bench--1.0.sql
 create mode 100644 contrib/pg_checksum_bench/pg_checksum_bench.c
 create mode 100644 contrib/pg_checksum_bench/pg_checksum_bench.control
 create mode 100644 contrib/pg_checksum_bench/sql/pg_checksum_bench.sql

diff --git a/contrib/meson.build b/contrib/meson.build
index ed30ee7d639..fe5149aadff 100644
--- a/contrib/meson.build
+++ b/contrib/meson.build
@@ -12,6 +12,7 @@ contrib_doc_args = {
   'install_dir': contrib_doc_dir,
 }
 
+subdir('pg_checksum_bench')
 subdir('amcheck')
 subdir('auth_delay')
 subdir('auto_explain')
diff --git a/contrib/pg_checksum_bench/meson.build b/contrib/pg_checksum_bench/meson.build
new file mode 100644
index 00000000000..32ccd9efa0f
--- /dev/null
+++ b/contrib/pg_checksum_bench/meson.build
@@ -0,0 +1,23 @@
+# Copyright (c) 2022-2025, PostgreSQL Global Development Group
+
+pg_checksum_bench_sources = files(
+  'pg_checksum_bench.c',
+)
+
+if host_system == 'windows'
+  pg_checksum_bench_sources += rc_lib_gen.process(win32ver_rc, extra_args: [
+    '--NAME', 'pg_checksum_bench',
+    '--FILEDESC', 'pg_checksum_bench',])
+endif
+
+pg_checksum_bench = shared_module('pg_checksum_bench',
+  pg_checksum_bench_sources,
+  kwargs: contrib_mod_args,
+)
+contrib_targets += pg_checksum_bench
+
+install_data(
+  'pg_checksum_bench--1.0.sql',
+  'pg_checksum_bench.control',
+  kwargs: contrib_data_args,
+)
diff --git a/contrib/pg_checksum_bench/pg_checksum_bench--1.0.sql b/contrib/pg_checksum_bench/pg_checksum_bench--1.0.sql
new file mode 100644
index 00000000000..5f13cbe3c5e
--- /dev/null
+++ b/contrib/pg_checksum_bench/pg_checksum_bench--1.0.sql
@@ -0,0 +1,8 @@
+/* contrib/pg_checksum_bench/pg_checksum_bench--1.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+-- \echo Use "CREATE EXTENSION pg_checksum_bench" to load this file. \quit
+
+CREATE FUNCTION drive_pg_checksum(page_count int)
+	RETURNS pg_catalog.void
+	AS 'MODULE_PATHNAME' LANGUAGE C;
diff --git a/contrib/pg_checksum_bench/pg_checksum_bench.c b/contrib/pg_checksum_bench/pg_checksum_bench.c
new file mode 100644
index 00000000000..dc20395a590
--- /dev/null
+++ b/contrib/pg_checksum_bench/pg_checksum_bench.c
@@ -0,0 +1,42 @@
+#include "postgres.h"
+#include "fmgr.h"
+#include "port/checksum.h"
+#include "port/checksum_impl.h"
+
+#include <stdio.h>
+#include <assert.h>
+
+PG_MODULE_MAGIC;
+
+#define REPEATS 1000000
+
+PG_FUNCTION_INFO_V1(drive_pg_checksum);
+Datum
+drive_pg_checksum(PG_FUNCTION_ARGS)
+{
+	int			page_count = PG_GETARG_INT32(0);
+	PGChecksummablePage *pages;
+	int			i;
+	size_t		j;
+
+	pages = palloc(page_count * sizeof(PGChecksummablePage));
+	srand(0);
+	for (j = 0; j < page_count * sizeof(PGChecksummablePage); j++)
+	{
+		char	   *byte_ptr = (char *) pages;
+
+		byte_ptr[j] = rand() % 256;
+	}
+
+	for (i = 0; i < REPEATS; i++)
+	{
+		const PGChecksummablePage *test_page = pages + (i % page_count);
+		volatile uint32 result = pg_checksum_block_choose((const char *) test_page);
+
+		(void) result;
+	}
+
+	pfree((void *) pages);
+
+	PG_RETURN_VOID();
+}
diff --git a/contrib/pg_checksum_bench/pg_checksum_bench.control b/contrib/pg_checksum_bench/pg_checksum_bench.control
new file mode 100644
index 00000000000..4a4e2c9363c
--- /dev/null
+++ b/contrib/pg_checksum_bench/pg_checksum_bench.control
@@ -0,0 +1,4 @@
+comment = 'pg_checksum benchmark'
+default_version = '1.0'
+module_pathname = '$libdir/pg_checksum_bench'
+relocatable = true
diff --git a/contrib/pg_checksum_bench/sql/pg_checksum_bench.sql b/contrib/pg_checksum_bench/sql/pg_checksum_bench.sql
new file mode 100644
index 00000000000..4b347699953
--- /dev/null
+++ b/contrib/pg_checksum_bench/sql/pg_checksum_bench.sql
@@ -0,0 +1,17 @@
+CREATE EXTENSION pg_checksum_bench;
+
+SELECT drive_pg_checksum(-1);
+
+\timing on
+
+SELECT drive_pg_checksum(1);
+SELECT drive_pg_checksum(2);
+SELECT drive_pg_checksum(4);
+SELECT drive_pg_checksum(8);
+SELECT drive_pg_checksum(16);
+SELECT drive_pg_checksum(32);
+SELECT drive_pg_checksum(64);
+SELECT drive_pg_checksum(128);
+SELECT drive_pg_checksum(256);
+SELECT drive_pg_checksum(512);
+SELECT drive_pg_checksum(1024);
-- 
2.43.0