8a0f9cf3a7
There is a problem with TCP zcopy enabled:
1. TCP initiator sends icreq and start polling a qpair. Polling of qpair
actively calls nvme_tcp_read_pdu function
2. nvme_tcp_read_pdu: qpair is in NVME_TCP_PDU_RECV_STATE_AWAIT_PDU_CH state,
it reads 8 bytes of common PDU header. It determines the type of the PDU
and finds the size of PDU_PSH header.
3. nvme_tcp_read_pdu: qpair is in NVME_TCP_PDU_RECV_STATE_AWAIT_PDU_PSH state.
It should read 120 bytes of icresp PDU. The number of bytes which needs to be
read is pdu->psh_len - pdu->psh_valid_bytes. qpair receives 120 bytes
(the full PDU) and calls nvme_tcp_pdu_psh_handle -> nvme_tcp_icresp_handle.
Here we check that we haven't yet received buffer reclaim notification and
simply return from this function. At the same time we continue to poll the qpair.
4. nvme_tcp_read_pdu: qpair is in NVME_TCP_PDU_RECV_STATE_AWAIT_PDU_PSH state
and tries to read data from a socket again. The number of bytes is
pdu->psh_len - pdu->psh_valid_bytes. But now pdu->psh_len == pdu->psh_valid_bytes,
so we call nvme_tcp_read_data with zero length.
readv with zero length is commonly used to check errors on the socket,
but in our case there is no errors and readv returns 0.
5. nvme_tcp_read_data treats zero as error and return NVME_TCP_CONNECTION_FATAL.
Fix is to handle icresp, but leave qpair in INITIALIZING state until
we receive acknowledgement for icreqsend_ack. We also move qpair to
NVME_TCP_PDU_RECV_STATE_AWAIT_PDU_READY recv_state so recv_pdu
will be zerofied and qpair will try to read a common PDU header.
But since it is not initialized yet, it won't receive anything
from the target.
Fixes issue #1633
Signed-off-by: Alexey Marchuk <alexeymar@mellanox.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4969 (master)
(cherry picked from commit
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| examples | ||
| go | ||
| include | ||
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| autopackage.sh | ||
| autorun_post.py | ||
| autorun.sh | ||
| autotest.sh | ||
| CHANGELOG.md | ||
| CONFIG | ||
| configure | ||
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| README.md | ||
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
- AWS
- Advanced Build Options
- Shared libraries
- 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.
The scripts/pkgdep.sh script will automatically install the bare minimum
dependencies required to build SPDK.
Use --help to see information on installing dependencies for optional components
./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 been tested on MacOS, Ubuntu 16.04.2 LTS and Ubuntu 18.04.3 LTS with the VirtualBox and Libvirt provider. The VirtualBox Extension Pack or [Vagrant Libvirt] (https://github.com/vagrant-libvirt/vagrant-libvirt) 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.
AWS
The following setup is known to work on AWS:
Image: Ubuntu 18.04
Before running setup.sh, run modprobe vfio-pci
then: DRIVER_OVERRIDE=vfio-pci ./setup.sh
Advanced Build Options
Optional components and other build-time configuration are controlled by
settings in the Makefile configuration file in the root of the repository. CONFIG
contains the base settings for the configure script. This script generates a new
file, mk/config.mk, that contains final build settings. For advanced configuration,
there are a number of additional options to configure that may be used, or
mk/config.mk 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 mk/config.mk 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 overridden 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. Note, this includes the ability to build not only from DPDK sources, but also just with the includes and libraries installed via the dpdk and dpdk-devel packages. 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
values in mk/config.mk. This can be useful if you, for example, generate
a mk/config.mk using the configure script and then have one or two
options (i.e. debug builds) that you wish to turn on and off frequently.
Shared libraries
By default, the build of the SPDK yields static libraries against which
the SPDK applications and examples are linked.
Configure option --with-shared provides the ability to produce SPDK shared
libraries, in addition to the default static ones. Use of this flag also
results in the SPDK executables linked to the shared versions of libraries.
SPDK shared libraries by default, are located in ./build/lib. This includes
the single SPDK shared lib encompassing all of the SPDK static libs
(libspdk.so) as well as individual SPDK shared libs corresponding to each
of the SPDK static ones.
In order to start a SPDK app linked with SPDK shared libraries, make sure to do the following steps:
- run ldconfig specifying the directory containing SPDK shared libraries
- provide proper
LD_LIBRARY_PATH
If DPDK shared libraries are used, you may also need to add DPDK shared
libraries to LD_LIBRARY_PATH
Linux:
./configure --with-shared
make
ldconfig -v -n ./build/lib
LD_LIBRARY_PATH=./build/lib/:./dpdk/build/lib/ ./build/bin/spdk_tgt
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 activities, please refer to spdk.io