/usr/include/postgresql/pg_config_os.h is in libpq-dev 9.3.24-0ubuntu0.14.04.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | /* src/include/port/linux.h */
/*
* As of July 2007, all known versions of the Linux kernel will sometimes
* return EIDRM for a shmctl() operation when EINVAL is correct (it happens
* when the low-order 15 bits of the supplied shm ID match the slot number
* assigned to a newer shmem segment). We deal with this by assuming that
* EIDRM means EINVAL in PGSharedMemoryIsInUse(). This is reasonably safe
* since in fact Linux has no excuse for ever returning EIDRM; it doesn't
* track removed segments in a way that would allow distinguishing them from
* private ones. But someday that code might get upgraded, and we'd have
* to have a kernel version test here.
*/
#define HAVE_LINUX_EIDRM_BUG
/*
* Set the default wal_sync_method to fdatasync. With recent Linux versions,
* xlogdefs.h's normal rules will prefer open_datasync, which (a) doesn't
* perform better and (b) causes outright failures on ext4 data=journal
* filesystems, because those don't support O_DIRECT.
*/
#define PLATFORM_DEFAULT_SYNC_METHOD SYNC_METHOD_FDATASYNC
|