v2-0001-Fix-huge_pages-on-current-Windows.patch

From 9a1450ecbe291cfc92e97f49506db9f443c8cbe9 Mon Sep 17 00:00:00 2001
From: Michael Paquier <michael@paquier.xyz>
Date: Thu, 7 Jul 2022 16:51:18 +0900
Subject: [PATCH v2] Fix huge_pages on current Windows.

Since Windows 10 1703, it's necessary to pass a flag to MapViewOfFile()
to enable large pages at map time.

Reported-by: Okano Naoki
Author: Thomas Munro
Discussion: https://postgr.es/m/17448-0a96583a67edb1f7%40postgresql.org
---
 src/backend/port/win32_shmem.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/backend/port/win32_shmem.c b/src/backend/port/win32_shmem.c
index 6cf69411db..2f51da5a6a 100644
--- a/src/backend/port/win32_shmem.c
+++ b/src/backend/port/win32_shmem.c
@@ -216,6 +216,7 @@ PGSharedMemoryCreate(Size size,
 	SIZE_T		largePageSize = 0;
 	Size		orig_size = size;
 	DWORD		flProtect = PAGE_READWRITE;
+	DWORD		desiredAccess;
 
 	ShmemProtectiveRegion = VirtualAlloc(NULL, PROTECTIVE_REGION_SIZE,
 										 MEM_RESERVE, PAGE_NOACCESS);
@@ -353,12 +354,17 @@ retry:
 	if (!CloseHandle(hmap))
 		elog(LOG, "could not close handle to shared memory: error code %lu", GetLastError());
 
+	desiredAccess = FILE_MAP_WRITE | FILE_MAP_READ;
+
+	/* Set large pages if wanted. */
+	if ((flProtect & SEC_LARGE_PAGES) != 0)
+		desiredAccess |= FILE_MAP_LARGE_PAGES;
 
 	/*
 	 * Get a pointer to the new shared memory segment. Map the whole segment
 	 * at once, and let the system decide on the initial address.
 	 */
-	memAddress = MapViewOfFileEx(hmap2, FILE_MAP_WRITE | FILE_MAP_READ, 0, 0, 0, NULL);
+	memAddress = MapViewOfFileEx(hmap2, desiredAccess, 0, 0, 0, NULL);
 	if (!memAddress)
 		ereport(FATAL,
 				(errmsg("could not create shared memory segment: error code %lu", GetLastError()),
-- 
2.36.1