9317f72d09
There was some confusion from a user on whether thread=1 means only one thread is supported. So add some extra documentation around this section to clarify this a bit more, since the option is a bit confusing. Signed-off-by: Jim Harris <james.r.harris@intel.com> Change-Id: Ibcccd1759180e2e6c47e736d94ffbeafc405f7bb Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5995 Tested-by: SPDK CI Jenkins <sys_sgci@intel.com> Reviewed-by: Changpeng Liu <changpeng.liu@intel.com> Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com> Reviewed-by: <dongx.yi@intel.com> Community-CI: Mellanox Build Bot
Introduction
This directory contains a plug-in module for fio to enable use with SPDK. Fio is free software published under version 2 of the GPL license.
Compiling fio
Clone the fio source repository from https://github.com/axboe/fio
git clone https://github.com/axboe/fio
cd fio
Compile the fio code and install:
make
make install
Compiling SPDK
Clone the SPDK source repository from https://github.com/spdk/spdk
git clone https://github.com/spdk/spdk
cd spdk
git submodule update --init
Then, run the SPDK configure script to enable fio (point it to the root of the fio repository):
cd spdk
./configure --with-fio=/path/to/fio/repo <other configuration options>
Finally, build SPDK:
make
Note to advanced users: These steps assume you're using the DPDK submodule. If you are using your own version of DPDK, the fio plugin requires that DPDK be compiled with -fPIC. You can compile DPDK with -fPIC by modifying your DPDK configuration file and adding the line:
EXTRA_CFLAGS=-fPIC
Usage
To use the SPDK fio plugin with fio, specify the plugin binary using LD_PRELOAD when running fio and set ioengine=spdk_bdev in the fio configuration file (see example_config.fio in the same directory as this README).
LD_PRELOAD=<path to spdk repo>/build/fio/spdk_bdev fio
The fio configuration file must contain one new parameter:
spdk_json_conf=./examples/bdev/fio_plugin/bdev.json
You can specify which block device to run against by setting the filename parameter to the block device name:
filename=Malloc0
Or for NVMe devices:
filename=Nvme0n1
fio by default forks a separate process for every job. It also supports just spawning a separate thread in the same process for every job. The SPDK fio plugin is limited to this latter thread usage model, so fio jobs must also specify thread=1 when using the SPDK fio plugin. The SPDK fio plugin supports multiple threads - in this case, the "1" just means "use thread mode".
fio also currently has a race condition on shutdown if dynamically loading the ioengine by specifying the engine's full path via the ioengine parameter - LD_PRELOAD is recommended to avoid this race condition.
When testing random workloads, it is recommended to set norandommap=1. fio's random map processing consumes extra CPU cycles which will degrade performance over time with the fio_plugin since all I/O are submitted and completed on a single CPU core.