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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2010-12-08 20:01:09 -0500 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2010-12-08 20:01:09 -0500 |
| commit | 576477e73c4a9cb32c7471c1cec354fd5328140e (patch) | |
| tree | 57f198feef6d233848f9aebc2f3c2a2c51d473ff /src/include/port/linux.h | |
| parent | e620ee35b249b0af255ef788003d1c9edb815a35 (diff) | |
| download | postgresql-576477e73c4a9cb32c7471c1cec354fd5328140e.tar.gz | |
Force default wal_sync_method to be fdatasync on Linux.
Recent versions of the Linux system header files cause xlogdefs.h to
believe that open_datasync should be the default sync method, whereas
formerly fdatasync was the default on Linux. open_datasync is a bad
choice, first because it doesn't actually outperform fdatasync (in fact
the reverse), and second because we try to use O_DIRECT with it, causing
failures on certain filesystems (e.g., ext4 with data=journal option).
This part of the patch is largely per a proposal from Marti Raudsepp.
More extensive changes are likely to follow in HEAD, but this is as much
change as we want to back-patch.
Also clean up confusing code and incorrect documentation surrounding the
fsync_writethrough option. Those changes shouldn't result in any actual
behavioral change, but I chose to back-patch them anyway to keep the
branches looking similar in this area.
In 9.0 and HEAD, also do some copy-editing on the WAL Reliability
documentation section.
Back-patch to all supported branches, since any of them might get used
on modern Linux versions.
Diffstat (limited to 'src/include/port/linux.h')
| -rw-r--r-- | src/include/port/linux.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/include/port/linux.h b/src/include/port/linux.h index b9498b239d..bcaa42dc4e 100644 --- a/src/include/port/linux.h +++ b/src/include/port/linux.h @@ -12,3 +12,11 @@ * 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 |