From 7e8a4457c8640fd62cf562e98c0b0df9ae80157f Mon Sep 17 00:00:00 2001 From: Ashutosh Bapat Date: Thu, 22 Jan 2026 20:48:36 +0530 Subject: [PATCH v20260123] Remove PG_MMAP_FLAGS Though the macro seems to be something meant to be used for all mmap calls, it is actually used only in CreateAnonymousSegment(). Other calls to mmap() use different set of flags. The macros was introduced in commit b0fc0df9364d2d2d17c0162cf3b8b59f6cb09f67, but was never used for portability. Remove it and use the flags directly in CreateAnonymousSegment(). Author: Ashutosh Bapat Suggested by: Peter Eisentraut Discussion: https://www.postgresql.org/message-id/12add41a-7625-4639-a394-a5563e349322@eisentraut.org --- src/backend/port/sysv_shmem.c | 10 ++++++---- src/include/portability/mem.h | 2 -- 2 files changed, 6 insertions(+), 6 deletions(-) diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c index de491897118..0f4ecac16e8 100644 --- a/src/backend/port/sysv_shmem.c +++ b/src/backend/port/sysv_shmem.c @@ -601,6 +601,8 @@ CreateAnonymousSegment(Size *size) Size allocsize = *size; void *ptr = MAP_FAILED; int mmap_errno = 0; + int mmap_flags = (MAP_SHARED | MAP_ANONYMOUS | MAP_HASSEMAPHORE); + #ifndef MAP_HUGETLB /* PGSharedMemoryCreate should have dealt with this case */ @@ -612,15 +614,15 @@ CreateAnonymousSegment(Size *size) * Round up the request size to a suitable large value. */ Size hugepagesize; - int mmap_flags; + int huge_mmap_flags; - GetHugePageSize(&hugepagesize, &mmap_flags); + GetHugePageSize(&hugepagesize, &huge_mmap_flags); if (allocsize % hugepagesize != 0) allocsize += hugepagesize - (allocsize % hugepagesize); ptr = mmap(NULL, allocsize, PROT_READ | PROT_WRITE, - PG_MMAP_FLAGS | mmap_flags, -1, 0); + mmap_flags | huge_mmap_flags, -1, 0); mmap_errno = errno; if (huge_pages == HUGE_PAGES_TRY && ptr == MAP_FAILED) elog(DEBUG1, "mmap(%zu) with MAP_HUGETLB failed, huge pages disabled: %m", @@ -644,7 +646,7 @@ CreateAnonymousSegment(Size *size) */ allocsize = *size; ptr = mmap(NULL, allocsize, PROT_READ | PROT_WRITE, - PG_MMAP_FLAGS, -1, 0); + mmap_flags, -1, 0); mmap_errno = errno; } diff --git a/src/include/portability/mem.h b/src/include/portability/mem.h index 091328f680d..c048e8836c5 100644 --- a/src/include/portability/mem.h +++ b/src/include/portability/mem.h @@ -38,8 +38,6 @@ #define MAP_NOSYNC 0 #endif -#define PG_MMAP_FLAGS (MAP_SHARED|MAP_ANONYMOUS|MAP_HASSEMAPHORE) - /* Some really old systems don't define MAP_FAILED. */ #ifndef MAP_FAILED #define MAP_FAILED ((void *) -1) base-commit: f9a468c664a4605e3080383ffaa302057d56feb1 -- 2.34.1