X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=3d9229338a11c9628f18d61a2a13e6cdc8b1c263;hp=3d6b354b87b7df40f723c497ab82b1424cd287f6;hb=4d4e80f2b4260f2c8b37a8612ce655502a799f7a;hpb=1d2af02a16fc3c3561c994be4de887b926b2b774

diff --git a/HOWTO b/HOWTO
index 3d6b354b..3d922933 100644
--- a/HOWTO
+++ b/HOWTO
@@ -219,6 +219,25 @@ filename=str	Fio normally makes up a filename based on the job name,
 opendir=str	Tell fio to recursively add any file it can find in this
 		directory and down the file system tree.
 
+lockfile=str	Fio defaults to not doing any locking files before it does
+		IO to them. If a file or file descriptor is shared, fio
+		can serialize IO to that file to make the end result
+		consistent. This is usual for emulating real workloads that
+		share files. The lock modes are:
+
+			none		No locking. The default.
+			exclusive	Only one thread/process may do IO,
+					excluding all others.
+			readwrite	Read-write locking on the file. Many
+					readers may access the file at the
+					same time, but writes get exclusive
+					access.
+
+		The option may be post-fixed with a lock batch number. If
+		set, then each thread/process may do that amount of IOs to
+		the file before giving up the lock. Since lock acqusition is
+		expensive, batching the lock/unlocks will speed up IO.
+
 readwrite=str
 rw=str		Type of io pattern. Accepted values are:
 
@@ -344,7 +363,7 @@ ioengine=str	Defines how the job issues io to the file. The following
 
 			psync 	Basic pread(2) or pwrite(2) io.
 
-			vsync	Basic readv(2) or writev(3) IO.
+			vsync	Basic readv(2) or writev(2) IO.
 
 			libaio	Linux native asynchronous io.
 
@@ -383,7 +402,10 @@ ioengine=str	Defines how the job issues io to the file. The following
 				cycles according to the cpuload= and
 				cpucycle= options. Setting cpuload=85
 				will cause that job to do nothing but burn
-				85% of the CPU.
+				85% of the CPU. In case of SMP machines,
+				use numjobs=<no_of_cpu> to get desired CPU
+				usage, as the cpuload only loads a single
+				CPU at the desired rate.
 
 			guasi	The GUASI IO engine is the Generic Userspace
 				Asyncronous Syscall Interface approach