v12-0002-Attempt-to-make-benchmark-more-sensitive-to-late.patch
text/x-patch
Filename: v12-0002-Attempt-to-make-benchmark-more-sensitive-to-late.patch
Type: text/x-patch
Part: 4
Patch
Same data as JSON:
GET /api/v1/attachments/:id/patch
the parsed metadata as JSON — format, series position, per-file stats; never the diff bytes.
API reference →
Format: format-patch
Series: patch v12-0002
Subject: Attempt to make benchmark more sensitive to latency
| File | + | − |
|---|---|---|
| contrib/test_crc32c/test_crc32c.c | 10 | 6 |
From 7a9b94677da30db0f8c296fe71037f65b157bc1c Mon Sep 17 00:00:00 2001
From: John Naylor <john.naylor@postgresql.org>
Date: Wed, 5 Mar 2025 07:52:52 +0700
Subject: [PATCH v12 2/6] Attempt to make benchmark more sensitive to latency
---
contrib/test_crc32c/test_crc32c.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/contrib/test_crc32c/test_crc32c.c b/contrib/test_crc32c/test_crc32c.c
index 28bc42de314..3e5ebad4e39 100644
--- a/contrib/test_crc32c/test_crc32c.c
+++ b/contrib/test_crc32c/test_crc32c.c
@@ -21,13 +21,13 @@ drive_crc32c(PG_FUNCTION_ARGS)
{
int64 count = PG_GETARG_INT32(0);
int64 num = PG_GETARG_INT32(1);
- char* data = malloc((size_t)num);
- pg_crc32c crc;
+ char* data = malloc((size_t)num + 256);
+ pg_crc32c crc = 0;
pg_prng_state state;
uint64 seed = 42;
pg_prng_seed(&state, seed);
/* set random data */
- for (uint64 i = 0; i < num; i++)
+ for (uint64 i = 0; i < num + 256; i++)
{
data[i] = pg_prng_uint32(&state) % 255;
}
@@ -36,11 +36,15 @@ drive_crc32c(PG_FUNCTION_ARGS)
while(count--)
{
- INIT_CRC32C(crc);
- COMP_CRC32C(crc, data, num);
- FIN_CRC32C(crc);
+ size_t delta = crc & 7;
+
+ /* make both pointer and length unpredictable */
+ COMP_CRC32C(crc, data + delta, num + delta);
+ /* simulate WAL header */
+ COMP_CRC32C(crc, data + delta, 20);
}
+ FIN_CRC32C(crc);
free((void *)data);
PG_RETURN_INT64((int64_t)crc);
--
2.48.1