Add the file sharing bits
When you use the same filename for several jobs now, they will share
the same file structure. Enable locking through two new options:
- lockfile. If set, a semaphore is associated with the file and it is
held from ->prep() to ->queue() has done its work.
- lockfile_batch. This controls how many IOs the job gets to do per
semaphore acqusition.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/HOWTO b/HOWTO
index d8c6b94..3e0a31b 100644
--- a/HOWTO
+++ b/HOWTO
@@ -219,6 +219,14 @@
opendir=str Tell fio to recursively add any file it can find in this
directory and down the file system tree.
+lockfile=bool If set, fio will lock a file internally before doing IO to it.
+ This makes it safe to share file descriptors across fio
+ jobs that run at the same time.
+
+lockfile_batch=int Acquiring a semaphore can be quite expensive, so
+ allow a process to complete this number of IOs before releasing
+ the semaphore again. Defaults to 1.
+
readwrite=str
rw=str Type of io pattern. Accepted values are: