From 817a64f323b058b0e0079ec2b76178370a24d82c Mon Sep 17 00:00:00 2001 From: Ashutosh Bapat Date: Fri, 30 Oct 2026 15:50:36 +0530 Subject: [PATCH v20261030 1/2] pg_get_shmem_pagesize() on Windows pg_get_shmem_pagesize() calls GetHugePageSize() when huge pages are in use. On Windows, however, GetHugePageSize() is a compatibility stub that returns zero, so the accessor returns zero rather than the large-page size. Use GetLargePageMinimum() instead on Windows when large pages are in use. Leave ordinary-page handling and the GetHugePageSize() stub unchanged, preserving existing shared_memory_size_in_huge_pages reporting. The only current caller of pg_get_shmem_pagesize() is the NUMA shared memory reporting function, which rejects unsupported platforms before calling this accessor. Thus, the faulty path is not currently reached by that caller on Windows. But this may change in future, hence fixing proactively. No backporting required since the bug does not impact anything. Author: Ashutosh Bapat Reviewed-by: TBD Discussion: https://postgr.es/m/ Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --- src/backend/storage/ipc/shmem.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/backend/storage/ipc/shmem.c b/src/backend/storage/ipc/shmem.c index 8d81893b470..2d944e21ab8 100644 --- a/src/backend/storage/ipc/shmem.c +++ b/src/backend/storage/ipc/shmem.c @@ -1390,7 +1390,11 @@ pg_get_shmem_pagesize(void) Assert(huge_pages_status != HUGE_PAGES_UNKNOWN); if (huge_pages_status == HUGE_PAGES_ON) +#ifdef WIN32 + os_page_size = GetLargePageMinimum(); +#else GetHugePageSize(&os_page_size, NULL); +#endif return os_page_size; } base-commit: 4f89416c9dbc78da5679d32072315af56fbeb8ed -- 2.34.1