History

Niklas Cassel af72965519 bdev/fio_plugin: fix scan-build error spdk_fio_init_thread() assigns td->io_ops_data. spdk_fio_init_thread() can return an error, but currently lacks error handling code. Add error handling code, and add an assertion that fio_thread (td->io_ops_data) is assigned when spdk_fio_init_thread() didn't return an error. Signed-off-by: Niklas Cassel <niklas.cassel@wdc.com> Change-Id: I8de7d59db0373599c90aa57fffa476c6707b6104 Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/7732 Community-CI: Broadcom CI Community-CI: Mellanox Build Bot Tested-by: SPDK CI Jenkins <sys_sgci@intel.com> Reviewed-by: Jim Harris <james.r.harris@intel.com> Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>		2021-05-07 11:41:46 +00:00
..
.gitignore	bdev: Add an example fio plugin	2017-08-04 20:03:37 -04:00
bdev.json	bdev_fio: remove legacy config support	2020-10-21 20:46:20 +00:00
example_config.fio	bdev_fio: remove legacy config support	2020-10-21 20:46:20 +00:00
fio_plugin.c	bdev/fio_plugin: fix scan-build error	2021-05-07 11:41:46 +00:00
full_bench.fio	doc: remove mentions of legacy config	2020-10-22 17:08:41 +00:00
Makefile	build: use DEPDIRS variables to build SPDK_LIB_LIST	2020-12-18 09:40:01 +00:00
README.md	fio_plugin: clarify thread=1	2021-01-20 08:45:21 +00:00

README.md

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.