smalloc: cleanups and allow sfree(NULL)

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 3d9229338a11c9628f18d61a2a13e6cdc8b1c263..32e7322cdc5155d3d6c2a1bf7875acbcd0cb7c2c 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -454,7 +454,11 @@ 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.
 
-overwrite=bool If writing to a file, setup the file first and do overwrites.
+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
+               and is large enough for the specified write phase, nothing
+               will be done.
 
 end_fsync=bool If true, fsync file contents when the job exits.
 
@@ -462,10 +466,6 @@ fsync_on_close=bool        If true, fio will fsync() a dirty file on close.
                This differs from end_fsync in that it will happen on every
                file close, not just at the end of the job.
 
-rwmixcycle=int Value in milliseconds describing how often to switch between
-               reads and writes for a mixed workload. The default is
-               500 msecs.
-
 rwmixread=int  How large a percentage of the mix should be reads.
 
 rwmixwrite=int How large a percentage of the mix should be writes. If both
@@ -482,6 +482,12 @@ norandommap        Normally fio will cover every block of the file when doing
                fio doesn't track potential block rewrites which may alter
                the calculated checksum for that block.
 
+softrandommap  See norandommap. If fio runs with the random block map enabled
+               and it fails to allocate the map, if this option is set it
+               will continue without a random block map. As coverage will
+               not be as complete as with random maps, this option is
+               disabled by default.
+
 nice=int       Run the job with the given nice value. See man nice(2).
 
 prio=int       Set the io priority value of this job. Linux limits us to