diff options
| author | Neeraj Singh <neerajsi@microsoft.com> | 2022-03-11 01:43:20 +0300 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2022-03-11 02:10:22 +0300 |
| commit | abf38abec201cded6094801766d69e11a6c112b6 (patch) | |
| tree | f1258b40f52f600be015a365ae5e57ed3b977a33 /configure.ac | |
| parent | 19d3f228c8df7e946278c96fb52acf1cea0f6a7a (diff) | |
core.fsyncmethod: add writeout-only mode
This commit introduces the `core.fsyncMethod` configuration
knob, which can currently be set to `fsync` or `writeout-only`.
The new writeout-only mode attempts to tell the operating system to
flush its in-memory page cache to the storage hardware without issuing a
CACHE_FLUSH command to the storage controller.
Writeout-only fsync is significantly faster than a vanilla fsync on
common hardware, since data is written to a disk-side cache rather than
all the way to a durable medium. Later changes in this patch series will
take advantage of this primitive to implement batching of hardware
flushes.
When git_fsync is called with FSYNC_WRITEOUT_ONLY, it may fail and the
caller is expected to do an ordinary fsync as needed.
On Apple platforms, the fsync system call does not issue a CACHE_FLUSH
directive to the storage controller. This change updates fsync to do
fcntl(F_FULLFSYNC) to make fsync actually durable. We maintain parity
with existing behavior on Apple platforms by setting the default value
of the new core.fsyncMethod option.
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'configure.ac')
| -rw-r--r-- | configure.ac | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index 5ee25ec95c..6bd6bef1c4 100644 --- a/configure.ac +++ b/configure.ac @@ -1082,6 +1082,14 @@ AC_COMPILE_IFELSE([CLOCK_MONOTONIC_SRC], [AC_MSG_RESULT([no]) HAVE_CLOCK_MONOTONIC=]) GIT_CONF_SUBST([HAVE_CLOCK_MONOTONIC]) + +# +# Define HAVE_SYNC_FILE_RANGE=YesPlease if sync_file_range is available. +GIT_CHECK_FUNC(sync_file_range, + [HAVE_SYNC_FILE_RANGE=YesPlease], + [HAVE_SYNC_FILE_RANGE]) +GIT_CONF_SUBST([HAVE_SYNC_FILE_RANGE]) + # # Define NO_SETITIMER if you don't have setitimer. GIT_CHECK_FUNC(setitimer, |