From: Jens Axboe <jens.axboe@oracle.com>
Date: Tue, 9 Mar 2010 19:49:54 +0000 (+0100)
Subject: Add documentation for 'sync_file_range'
X-Git-Tag: fio-1.38~23
X-Git-Url: https://git.kernel.dk/?p=fio.git;a=commitdiff_plain;h=e76b1da43606f86fc23c8acb63114cba0d80a1c7;hp=3843deb322eb7b54d2d19d7b1ce19c5dc44d57ff

Add documentation for 'sync_file_range'

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/HOWTO b/HOWTO
index 886515b7..6c7f05b9 100644
--- a/HOWTO
+++ b/HOWTO
@@ -566,11 +566,25 @@ fsync=int	If writing to a file, issue a sync of the dirty data
 		not sync the file. The exception is the sg io engine, which
 		synchronizes the disk cache anyway.
 
-fsyncdata=int	Like fsync= but uses fdatasync() to only sync data and not
+fdatasync=int	Like fsync= but uses fdatasync() to only sync data and not
 		metadata blocks.
 		In FreeBSD there is no fdatasync(), this falls back to
 		using fsync()
 
+sync_file_range=str:val	Use sync_file_range() for every 'val' number of
+		write operations. Fio will track range of writes that
+		have happened since the last sync_file_range() call. 'str'
+		can currently be one or more of:
+
+		wait_before	SYNC_FILE_RANGE_WAIT_BEFORE
+		write		SYNC_FILE_RANGE_WRITE
+		wait_after	SYNC_FILE_RANGE_WAIT_AFTER
+
+		So if you do sync_file_range=wait_before,write:8, fio would
+		use SYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE for
+		every 8 writes. Also see the sync_file_range(2) man page.
+		This option is Linux specific.
+
 overwrite=bool	If true, writes to a file will always overwrite existing
 		data. If the file doesn't already exist, it will be
 		created before the write phase begins. If the file exists
diff --git a/fio.1 b/fio.1
index 60f787a1..5d0988b2 100644
--- a/fio.1
+++ b/fio.1
@@ -380,6 +380,27 @@ How many I/Os to perform before issuing an \fBfsync\fR\|(2) of dirty data.  If
 Like \fBfsync\fR, but uses \fBfdatasync\fR\|(2) instead to only sync the
 data parts of the file. Default: 0.
 .TP
+.BI sync_file_range \fR=\fPstr:int
+Use sync_file_range() for every \fRval\fP number of write operations. Fio will
+track range of writes that have happened since the last sync_file_range() call.
+\fRstr\fP can currently be one or more of:
+.RS
+.TP
+.B wait_before
+SYNC_FILE_RANGE_WAIT_BEFORE
+.TP
+.B write
+SYNC_FILE_RANGE_WRITE
+.TP
+.B wait_after
+SYNC_FILE_RANGE_WRITE
+.TP
+.RE
+.P
+So if you do sync_file_range=wait_before,write:8, fio would use
+\fBSYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE\fP for every 8 writes.
+Also see the sync_file_range(2) man page.  This option is Linux specific.
+.TP
 .BI overwrite \fR=\fPbool
 If writing, setup the file first and do overwrites.  Default: false.
 .TP