671b77e5cd
The intents of these arrays was to keep track in the bdev layer of all base<->virtual bdev relationships - i.e. which member disk bdevs make up a RAID bdev, which logical volume bdevs are associated with a bdev that contains an lvolstore, etc. Currently none of this is used however. And trying to keep track in the bdev layer instead of asking the bdev modules for the relationships has a number of complications. Early one, we tried to do this with TAILQs - but that doesn't work since this can't be done with a single TAILQ_ENTRY in the bdev structures. So we moved to arrays - that works a bit better, but then the pointer arrays have to be realloc'd which isn't ideal. The biggest problem though with these arrays is that they held bdev pointers - not bdev descriptor pointers. It's not really valid to access bdevs without a descriptor - the descriptors are what make sure active references are accounted for when a bdev is hotplugged. Of course the bdev layer knows when a bdev is getting removed and could go and do the updates to these arrays separately - but that just seems very convoluted. So for now just remove these arrays completely. If there is a future need for the bdev layer to understand relationships between bdevs, we can add module APIs so that the generic layer can ask the modules about the relationships. Signed-off-by: Jim Harris <james.r.harris@intel.com> Change-Id: I99ef1068240bff1262f64f234260cf2fb44df51d Reviewed-on: https://review.gerrithub.io/420932 Tested-by: SPDK CI Jenkins <sys_sgci@intel.com> Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com> Reviewed-by: Changpeng Liu <changpeng.liu@intel.com> Reviewed-by: Ben Walker <benjamin.walker@intel.com> Reviewed-by: GangCao <gang.cao@intel.com>
Storage Performance Development Kit
The Storage Performance Development Kit (SPDK) provides a set of tools and libraries for writing high performance, scalable, user-mode storage applications. It achieves high performance by moving all of the necessary drivers into userspace and operating in a polled mode instead of relying on interrupts, which avoids kernel context switches and eliminates interrupt handling overhead.
The development kit currently includes:
- NVMe driver
- I/OAT (DMA engine) driver
- NVMe over Fabrics target
- iSCSI target
- vhost target
- Virtio-SCSI driver
In this readme:
- Documentation
- Prerequisites
- Source Code
- Build
- Unit Tests
- Vagrant
- Advanced Build Options
- Hugepages and Device Binding
- Example Code
- Contributing
Documentation
Doxygen API documentation is available, as well as a Porting Guide for porting SPDK to different frameworks and operating systems.
Source Code
git clone https://github.com/spdk/spdk
cd spdk
git submodule update --init
Prerequisites
The dependencies can be installed automatically by scripts/pkgdep.sh.
./scripts/pkgdep.sh
Build
Linux:
./configure
make
FreeBSD: Note: Make sure you have the matching kernel source in /usr/src/ and also note that CONFIG_COVERAGE option is not available right now for FreeBSD builds.
./configure
gmake
Unit Tests
./test/unit/unittest.sh
You will see several error messages when running the unit tests, but they are part of the test suite. The final message at the end of the script indicates success or failure.
Vagrant
A Vagrant setup is also provided to create a Linux VM with a virtual NVMe controller to get up and running quickly. Currently this has only been tested on MacOS and Ubuntu 16.04.2 LTS with the VirtualBox provider. The VirtualBox Extension Pack must also be installed in order to get the required NVMe support.
Details on the Vagrant setup can be found in the SPDK Vagrant documentation.
Advanced Build Options
Optional components and other build-time configuration are controlled by
settings in two Makefile fragments in the root of the repository. CONFIG
contains the base settings. Running the configure script generates a new
file, CONFIG.local, that contains overrides to the base CONFIG file. For
advanced configuration, there are a number of additional options to configure
that may be used, or CONFIG.local can simply be created and edited by hand. A
description of all possible options is located in CONFIG.
Boolean (on/off) options are configured with a 'y' (yes) or 'n' (no). For
example, this line of CONFIG controls whether the optional RDMA (libibverbs)
support is enabled:
CONFIG_RDMA?=n
To enable RDMA, this line may be added to CONFIG.local with a 'y' instead of
'n'. For the majority of options this can be done using the configure script.
For example:
./configure --with-rdma
Additionally, CONFIG options may also be overrriden on the make command
line:
make CONFIG_RDMA=y
Users may wish to use a version of DPDK different from the submodule included in the SPDK repository. To specify an alternate DPDK installation, run configure with the --with-dpdk option. For example:
Linux:
./configure --with-dpdk=/path/to/dpdk/x86_64-native-linuxapp-gcc
make
FreeBSD:
./configure --with-dpdk=/path/to/dpdk/x86_64-native-bsdapp-clang
gmake
The options specified on the make command line take precedence over the
default values in CONFIG and CONFIG.local. This can be useful if you, for
example, generate a CONFIG.local using the configure script and then have
one or two options (i.e. debug builds) that you wish to turn on and off
frequently.
Hugepages and Device Binding
Before running an SPDK application, some hugepages must be allocated and any NVMe and I/OAT devices must be unbound from the native kernel drivers. SPDK includes a script to automate this process on both Linux and FreeBSD. This script should be run as root.
sudo scripts/setup.sh
Users may wish to configure a specific memory size. Below is an example of configuring 8192MB memory.
sudo HUGEMEM=8192 scripts/setup.sh
Example Code
Example code is located in the examples directory. The examples are compiled automatically as part of the build process. Simply call any of the examples with no arguments to see the help output. You'll likely need to run the examples as a privileged user (root) unless you've done additional configuration to grant your user permission to allocate huge pages and map devices through vfio.
Contributing
For additional details on how to get more involved in the community, including contributing code and participating in discussions and other activiites, please refer to spdk.io