backend: Logging exec_{pre|post}run

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 8211c3b48166cd6f03e4f32d9beddf57cf1e03e2..794728f3b2cf3b3d9edc3a7493ce157c8a5901ea 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -568,6 +568,8 @@ ioengine=str        Defines how the job issues io to the file. The following
 
                        vsync   Basic readv(2) or writev(2) IO.
 
+                       psyncv  Basic preadv(2) or pwritev(2) IO.
+
                        libaio  Linux native asynchronous io. Note that Linux
                                may only support queued behaviour with
                                non-buffered IO (set direct=1 or buffered=0).
@@ -828,11 +830,15 @@ thinktime_spin=int
                to sleeping for the rest of the period specified by
                thinktime.
 
-thinktime_blocks
+thinktime_blocks=int
                Only valid if thinktime is set - control how many blocks
                to issue, before waiting 'thinktime' usecs. If not set,
                defaults to 1 which will make fio wait 'thinktime' usecs
-               after every block.
+               after every block. This effectively makes any queue depth
+               setting redundant, since no more than 1 IO will be queued
+               before we have to complete it and do our thinktime. In
+               other words, this setting effectively caps the queue depth
+               if the latter is larger.
 
 rate=int       Cap the bandwidth used by this job. The number is in bytes/sec,
                the normal suffix rules apply. You can use rate=500k to limit
@@ -1230,7 +1236,7 @@ write_lat_log=str Same as write_bw_log, except that this option stores io
 
                write_lat_log=foo
 
-               The actual log names will be foo_slat.log, foo_slat.log,
+               The actual log names will be foo_slat.log, foo_clat.log,
                and foo_lat.log. This helps fio_generate_plot fine the logs
                automatically.