Robert Schmidt
7d4f7ebbfe
Deadlock avoidance in rfsimulator
This change introduces a countermeasure for deadlock in rfsimulator. The
deadlock happens when all entities are waiting for new data to come in,
and happens with 2+ clients, when a new client connects. I think this
issue is due to ordering of fullwrite calls, resulting in out-of-order
delivery of packets and eventually trashing the packets on the receiving
side. The out-of-order delivery warnings are printed just before the
system deadlocks but I have not found a better solution so far. The
workaround makes the server never lock up permanently by ignoring the
client failure to write on time after 10 tries.
This was tested locally for both UE as server and gNB as server and
works correctly, causing the deadlock to clear and the added log to be
printed several times when the deadlock is detected, after which the
system goes back to normal.
I have some gdb output of the executables during deadlock:
UE:
$7 = {conn_sock = 98, lastReceivedTS = 3226163740, headerMode = true, trashingPacket = false, th = {size = 13184, nbAnt = 1, timestamp = 3226150556, option_value = 0, option_flag = 0}, transferPtr = 0x7f6a500018a8 "\200\063", remainToTransfer = 24,
circularBufEnd = 0x7f6a503b3ac0 "", circularBuf = 0x7f6a501f1ac0, channel_model = 0x0}
(gdb) p t->buf[5]
$8 = {conn_sock = 97, lastReceivedTS = 0, headerMode = true, trashingPacket = false, th = {size = 0, nbAnt = 0, timestamp = 0, option_value = 0, option_flag = 0}, transferPtr = 0x7f6a50001900 "", remainToTransfer = 24, circularBufEnd = 0x7f6a50575ad0 "",
circularBuf = 0x7f6a503b3ad0, channel_model = 0x0}
nextRxTimestamp 3225937740
nsamps = 30720
gNB 1:
(gdb) p t->buf[0]
$4 = {conn_sock = 95, lastReceivedTS = 3226026876, headerMode = true, trashingPacket = false, th = {size = 1, nbAnt = 1, timestamp = 3226026875, option_value = 0, option_flag = 0},
transferPtr = 0x7f8dfc003ab8 "\001", remainToTransfer = 24, circularBufEnd = 0x7f8e1c3ff010 "", circularBuf = 0x7f8e1c23d010, channel_model = 0x0}
nextRxTimestamp 3225996956
gNB 2:
lastReceivedTS = 3226026875
$2 = {conn_sock = 95, lastReceivedTS = 3226026875, headerMode = true, trashingPacket = false, th = {size = 1, nbAnt = 1, timestamp = 3226026875, option_value = 0, option_flag = 0},
transferPtr = 0x744898003ab8 "\001", remainToTransfer = 24, circularBufEnd = 0x7448bc2e7010 "", circularBuf = 0x7448bc125010, channel_model = 0x0}
nextRxTimestamp 3226026875
As you can see all executables are in have_to_wait state.
OpenAirInterface License
It is distributed under OAI Public License V1.1.
The license information is distributed under LICENSE file in the same directory.
Please see NOTICE file for third party software that is included in the sources.
Where to Start
- General overview of documentation
- The implemented features
- System Requirements for Using OAI Stack
- How to build
- How to run the modems
Not all information is available in a central place, and information for specific sub-systems might be available in the corresponding sub-directories. To find all READMEs, this command might be handy:
find . -iname "readme*"
RAN repository structure
The OpenAirInterface (OAI) software is composed of the following parts:
openairinterface5g
├── charts
├── ci-scripts : Meta-scripts used by the OSA CI process. Contains also configuration files used day-to-day by CI.
├── CMakeLists.txt : Top-level CMakeLists.txt for building
├── cmake_targets : Build utilities to compile (simulation, emulation and real-time platforms), and generated build files.
├── common : Some common OAI utilities, some other tools can be found at openair2/UTILS.
├── doc : Documentation
├── docker : Dockerfiles to build for Ubuntu and RHEL
├── executables : Top-level executable source files (gNB, eNB, ...)
├── maketags : Script to generate emacs tags.
├── nfapi : (n)FAPI code for MAC-PHY interface
├── openair1 : Layer 1 (3GPP LTE Rel-10/12 PHY, NR Rel-15 PHY)
├── openair2 : Layer 2 (3GPP LTE Rel-10 MAC/RLC/PDCP/RRC/X2AP, LTE Rel-14 M2AP, NR Rel-15+ MAC/RLC/PDCP/SDAP/RRC/X2AP/F1AP/E1AP), E2AP
├── openair3 : Layer 3 (3GPP LTE Rel-10 S1AP/GTP, NR Rel-15 NGAP/GTP)
├── openshift : OpenShift helm charts for some deployment options of OAI
├── radio : Drivers for various radios such as USRP, AW2S, RFsim, 7.2 FHI, ...
├── targets : Some configuration files; only historical relevance, and might be deleted in the future
└── tools : Tools for use by the developers/ci machines: code analysis and formatting
How to get support from the OAI Community
You can ask your question on the mailing lists.
Your email should contain below information:
- A clear subject in your email.
- For all the queries there should be [Query] in the subject of the email and for problems there should be [Problem].
- In case of a problem, add a small description.
- Do not share any photos unless you want to share a diagram.
- OAI gNB/DU/CU/CU-CP/CU-UP configuration file in
.confformat only. - Logs of OAI gNB/DU/CU/CU-CP/CU-UP in
.logor.txtformat only. - In case your question is related to performance, include a small description of the machine (Operating System, Kernel version, CPU, RAM and networking card) and diagram of your testing environment.
- Known/open issues are present on GitLab, so keep checking.
Always remember a structured email will help us understand your issues quickly.