Add softrandommap and --alloc-size options

[fio.git] / README

diff --git a/README b/README
index e933bd55ef356a4eadebfc7bd1a9345ee094fd95..db8e6724ee7745d2c81f5ae2793ad6ebdd0f8d41 100644 (file)
--- a/README
+++ b/README
@@ -75,6 +75,8 @@ $ fio
        --readonly      Turn on safety read-only checks, preventing writes
        --eta=when      When ETA estimate should be printed
                        May be "always", "never" or "auto"
+       --section=name  Only run specified section in job file
+       --alloc-size=kb Set smalloc pool to this size in kb (def 1024)
 
 
 Any parameters following the options will be assumed to be job files,
@@ -98,11 +100,27 @@ options in fio. Currently the options are:
        blktrace        Dump info related to blktrace setup
        verify          Dump info related to IO verification
        all             Enable all debug options
+       random          Dump info related to random offset generation
+       parse           Dump info related to option matching and parsing
+       diskutil        Dump info related to disk utilization updates
        ? or help       Show available debug options.
 
 You can specify as many as you want, eg --debug=file,mem will enable
 file and memory debugging.
 
+The section switch is meant to make it easier to ship a bigger job file
+instead of several smaller ones. Say you define a job file with light,
+moderate, and heavy parts. Then you can ask fio to run the given part
+only by giving it a --section=heavy command line option. The section
+option only applies to job sections, the reserved 'global' section is
+always parsed and taken into account.
+
+Fio has an internal allocator for shared memory called smalloc. It
+allocates shared structures from this pool. The pool defaults to 1024k
+in size, and can grow to 32 pools. If running large jobs with randommap
+enabled it can run out of memory, in which case the --alloc-size switch
+is handy for starting with a larger pool size.
+
 
 Job file
 --------