X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=f61b4c1daab6b54831d5195dc36000be502461ab;hp=f4ebac94348eef97b46b70b80dce8d1e3130dda4;hb=73170f19408559ed7e318f93b21e5cbbf13725bd;hpb=61697c37566a211ad3fd70f46397d9b7675b0fc2

diff --git a/HOWTO b/HOWTO
index f4ebac94..f61b4c1d 100644
--- a/HOWTO
+++ b/HOWTO
@@ -49,7 +49,7 @@ bottom, it contains the following basic parameters:
 
 	IO engine	How do we issue io? We could be memory mapping the
 			file, we could be using regular read/write, we
-			could be using splice, async io, or even
+			could be using splice, async io, syslet, or even
 			SG (SCSI generic sg).
 
 	IO depth	If the io engine is async, how large a queuing
@@ -203,7 +203,9 @@ directory=str	Prefix filenames with this directory. Used to places files
 filename=str	Fio normally makes up a filename based on the job name,
 		thread number, and file number. If you want to share
 		files between threads in a job or several jobs, specify
-		a filename for each of them to override the default.
+		a filename for each of them to override the default. If
+		the ioengine used is 'net', the filename is the host and
+		port to connect to in the format of =host:port.
 
 rw=str		Type of io pattern. Accepted values are:
 
@@ -268,6 +270,9 @@ ioengine=str	Defines how the job issues io to the file. The following
 				vmsplice(2) to transfer data from user
 				space to the kernel.
 
+			syslet-rw Use the syslet system calls to make
+				regular read/write async.
+
 			sg	SCSI generic sg v3 io. May either be
 				synchronous using the SG_IO ioctl, or if
 				the target is an sg character device
@@ -278,6 +283,12 @@ ioengine=str	Defines how the job issues io to the file. The following
 				to. This is mainly used to exercise fio
 				itself and for debugging/testing purposes.
 
+			net	Transfer over the network to given host:port.
+				'filename' must be set appropriately to
+				filename=host:port regardless of send
+				or receive, if the latter only the port
+				argument is used.
+
 iodepth=int	This defines how many io units to keep in flight against
 		the file. The default is 1 for each file defined in this
 		job, can be overridden with a larger value for higher
@@ -545,6 +556,8 @@ Client1 (g=0): err= 0:
     bw (KiB/s) : min=    0, max= 1196, per=51.00%, avg=664.02, stdev=681.68
   cpu        : usr=1.49%, sys=0.25%, ctx=7969
   IO depths    : 1=0.1%, 2=0.3%, 4=0.5%, 8=99.0%, 16=0.0%, 32=0.0%, >32=0.0%
+     lat (msec): 2=1.6%, 4=0.0%, 8=3.2%, 16=12.8%, 32=38.4%, 64=24.8%, 128=15.2%
+     lat (msec): 256=4.0%, 512=0.0%, 1024=0.0%, >=2048=0.0%
 
 The client number is printed, along with the group id and error of that
 thread. Below is the io statistics, here for writes. In the order listed,
@@ -574,6 +587,12 @@ IO depths=	The distribution of io depths over the job life time. The
 		16= entries includes depths up to that value but higher
 		than the previous entry. In other words, it covers the
 		range from 16 to 31.
+IO latencies=	The distribution of IO completion latencies. This is the
+		time from when IO leaves fio and when it gets completed.
+		The numbers follow the same pattern as the IO depths,
+		meaning that 2=1.6% means that 1.6% of the IO completed
+		within 2 msecs, 16=12.8% means that 12.8% of the IO
+		took more than 8 msecs, but less than (or equal to) 16 msecs.
 
 After each client has been listed, the group statistics are printed. They
 will look like this: