pre_read fixes

[fio.git] / README

diff --git a/README b/README
index c5598109b6309a8cc44972f740fd95b664cf8c0b..480f1d0ef6d455efa1e49c672def112b0607e6c1 100644 (file)
--- a/README
+++ b/README
@@ -126,6 +126,7 @@ options in fio. Currently the options are:
        parse           Dump info related to option matching and parsing
        diskutil        Dump info related to disk utilization updates
        job:x           Dump info only related to job number x
+       mutex           Dump info only related to mutex up/down ops
        ? or help       Show available debug options.
 
 You can specify as many as you want, eg --debug=file,mem will enable
@@ -140,9 +141,11 @@ 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
+in size, and can grow to 128 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.
+is handy for starting with a larger pool size. The backing store is
+files in /tmp. Fio cleans up after itself, while it is running you
+may see .fio_smalloc.* files in /tmp.
 
 
 Job file
@@ -258,6 +261,33 @@ The job file parameters are:
        cpuchunks=x     Split burn cycles into pieces of x usecs.
 
 
+
+Platforms
+---------
+
+Fio works on (at least) Linux, Solaris, and FreeBSD. Some features and/or
+options may only be available on some of the platforms, typically because
+those features only apply to that platform (like the solarisaio engine, or
+the splice engine on Linux).
+
+Some features are not available on FreeBSD/Solaris even if they could be
+implemented, I'd be happy to take patches for that. An example of that is
+disk utility statistics and (I think) huge page support, support for that
+does exist in FreeBSD/Solaris.
+
+Fio uses pthread mutexes for signalling and locking and FreeBSD does not
+support process shared pthread mutexes. As a result, only threads are
+supported on FreeBSD. This could be fixed with sysv ipc locking or
+other locking alternatives.
+
+Other *BSD platforms are untested, but fio should work there almost out
+of the box. Since I don't do test runs or even compiles on those platforms,
+your mileage may vary. Sending me patches for other platforms is greatly
+appreciated. There's a lot of value in having the same test/benchmark tool
+available on all platforms.
+
+
+
 Author
 ------