fio: HOWTO update

In case of  cpuio , on smp machines we need increase numjobs
to <num of cpu's> to get the desired load across cpu's.
Just updated HOWTO with this info.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/HOWTO b/HOWTO
index 0d3d7759843b3b4bbbfa3375f1a7b73733e95930..d8c6b9414eef85be48779d7018682cf2bbd07470 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -383,7 +383,10 @@ 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
                                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
 
                        guasi   The GUASI IO engine is the Generic Userspace
                                Asyncronous Syscall Interface approach