9459848ce5
For large writes that require multiple SCSI tasks (one for immediate data, then one or more for R2T-solicited data), we bump the refcount for the task associated with the initial immediate data PDU, to ensure it does not get freed until all of the child tasks are completed. But in some cases this initial immediate data PDU could complete after all of the R2T-soliciated data PDUs. The completion code was not handling this case correctly which would result in the iSCSI connection thinking it still had outstanding SCSI tasks when the connection closed. Signed-off-by: Jim Harris <james.r.harris@intel.com> Change-Id: I9f9c5322755462d1918fde0075c87c84295cb10c
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-16.07.tar.xz
3) tar xf dpdk-16.07.tar.xz
Linux:
4) (cd dpdk-16.07 && make install T=x86_64-native-linuxapp-gcc DESTDIR=.)
FreeBSD:
4) (cd dpdk-16.07 && 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-16.07/x86_64-native-linuxapp-gcc
FreeBSD:
gmake DPDK_DIR=./dpdk-16.07/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.