If a blockdev module calls spdk_bdev_io_complete() within its submit_request function, and the user's completion callback issues a new I/O, it is possible to cause infinite recursion, consuming all available stack space. To avoid this, track whether a bdev_io is being processed by submit_request, and if io_complete() is called in this case, defer the completion via an event. Change-Id: I6ccdb8ed4ee0d5738e6c9840d35431de52bd5fa2 Signed-off-by: Daniel Verkamp <daniel.verkamp@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:
Documentation
Doxygen API documentation is available, as well as a Porting Guide for porting SPDK to different frameworks and operating systems.
Many examples are available in the examples
directory.
Prerequisites
To build SPDK, some dependencies must be installed.
Fedora/CentOS:
sudo dnf install -y gcc gcc-c++ CUnit-devel libaio-devel openssl-devel
# Additional dependencies for NVMe over Fabrics:
sudo dnf install -y libibverbs-devel librdmacm-devel
Ubuntu/Debian:
sudo apt-get install -y gcc g++ make libcunit1-dev libaio-dev libssl-dev
# Additional dependencies for NVMe over Fabrics:
sudo apt-get install -y libibverbs-dev librdmacm-dev
FreeBSD:
- gcc
- gmake
- cunit
- openssl
Additionally, DPDK is required.
1) cd /path/to/spdk
2) wget http://fast.dpdk.org/rel/dpdk-16.11.tar.xz
3) tar xf dpdk-16.11.tar.xz
Linux:
4) (cd dpdk-16.11 && make install T=x86_64-native-linuxapp-gcc DESTDIR=.)
FreeBSD:
4) (cd dpdk-16.11 && gmake install T=x86_64-native-bsdapp-clang DESTDIR=.)
Building
Once the prerequisites are installed, run 'make' within the SPDK directory to build the SPDK libraries and examples.
make DPDK_DIR=/path/to/dpdk
If you followed the instructions above for building DPDK:
Linux:
make DPDK_DIR=./dpdk-16.11/x86_64-native-linuxapp-gcc
FreeBSD:
gmake DPDK_DIR=./dpdk-16.11/x86_64-native-bsdapp-clang
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
Examples
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.