668847e150
nvme_ctrlr_process_io_completions() now takes a second parameter, max_completions, to let the user limit the number of I/Os completed on each poll. If there are many I/Os waiting to be completed, the nvme_ctrlr_process_io_completions() function could run for a long time before returning control to the user, so the max_completions parameter lets the user have more control of latency. Change-Id: I3173059d94ec1cc5dbb636fc0ffd3dc09f3bfe4b 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.
Documentation
Prerequisites
To build SPDK, some dependencies must be installed.
Fedora/CentOS:
- gcc
- libpciaccess-devel
- CUnit-devel
Ubuntu/Debian:
- gcc
- libpciaccess-dev
- make
- libcunit1-dev
FreeBSD:
- gcc
- libpciaccess
- gmake
- cunit
Additionally, DPDK is required.
1) cd /path/to/spdk
2) wget http://dpdk.org/browse/dpdk/snapshot/dpdk-2.1.0.tar.gz
3) tar xfz dpdk-2.1.0.tar.gz
4) cd dpdk-2.1.0
Linux:
5) make install T=x86_64-native-linuxapp-gcc
FreeBSD:
5) gmake install T=x86_64-native-bsdapp-clang
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=`pwd`/dpdk-2.1.0/x86_64-native-linuxapp-gcc
FreeBSD:
gmake DPDK_DIR=`pwd`/dpdk-2.1.0/x86_64-native-bsdapp-clang
Hugepages and Device Binding
Before running an SPDK application, some hugepages must be allocated and any NVMe devices must be unbound from the native NVMe kernel driver. SPDK includes scripts to automate this process on both Linux and FreeBSD.
1) scripts/configure_hugepages.sh
2) scripts/unbind_nvme.sh