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