X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=80b9e75a75cf52ba86b38f6e1addea8f4a118b52;hp=5d378f3d9a75cf7c0e1cd7ca95f65ecaee060d58;hb=dab41128322e7be477045a1cdd37b9c38c367aa5;hpb=8243be59aa35aa016fcbeee99353b08376953911

diff --git a/HOWTO b/HOWTO
index 5d378f3d..80b9e75a 100644
--- a/HOWTO
+++ b/HOWTO
@@ -543,6 +543,8 @@ Parameter types
 
 	If the option accepts an upper and lower range, use a colon ':' or
 	minus '-' to separate such values. See :ref:`irange <irange>`.
+	If the lower value specified happens to be larger than the upper value,
+	two values are swapped.
 
 .. _bool:
 
@@ -1100,13 +1102,15 @@ I/O type
 	blocks given. For example, if you give 32 as a parameter, fio will sync the
 	file for every 32 writes issued. If fio is using non-buffered I/O, we may
 	not sync the file. The exception is the sg I/O engine, which synchronizes
-	the disk cache anyway.
+	the disk cache anyway. Defaults to 0, which means no sync every certain
+	number of writes.
 
 .. option:: fdatasync=int
 
 	Like :option:`fsync` but uses :manpage:`fdatasync(2)` to only sync data and
 	not metadata blocks.  In Windows, FreeBSD, and DragonFlyBSD there is no
 	:manpage:`fdatasync(2)`, this falls back to using :manpage:`fsync(2)`.
+	Defaults to 0, which means no sync data every certain number of writes.
 
 .. option:: write_barrier=int
 
@@ -1571,6 +1575,7 @@ I/O engine
 		**sync**
 			Basic :manpage:`read(2)` or :manpage:`write(2)`
 			I/O. :manpage:`lseek(2)` is used to position the I/O location.
+			See :option:`fsync` and :option:`fdatasync` for syncing write I/Os.
 
 		**psync**
 			Basic :manpage:`pread(2)` or :manpage:`pwrite(2)` I/O.  Default on
@@ -1748,7 +1753,8 @@ caveat that when used on the command line, they must come after the
 
 .. option:: cpuload=int : [cpuio]
 
-	Attempt to use the specified percentage of CPU cycles.
+	Attempt to use the specified percentage of CPU cycles. This is a mandatory
+	option when using cpuio I/O engine.
 
 .. option:: cpuchunks=int : [cpuio]