fix blocking bugs in command nr_dlsim -n100 -e27 -s35 -b 273 -R273 -x4 -y4 -z4
errors in main OAI code:
- one stack overflow
- one variable array of size 0
- one direct usage of unaligned SIMD
and small fixes inside the tests tool nr_dlsim to handle this large configuration (4layers, 100MHz)
use a better complex vector multiplication function
- simplify the code
- prevent to use "beta" tables from one decoder run to the next one (to see it
is the case, don't initialize beta, you will see it doesn't decode)
- decrease memory footprint of the decoder by x10 or more
- save about 15% of cpu in polartest unitary test tool, and more if we run in
realistic use case
- still this decoder performs much worse than the (very) slow OAI version by 3dB
telnetsrv uses the Intel/AMD-specific "cpuid" instruction, which is not
available on ARM machines. Remove the call.
The previous code was checking for the number of cores, which is
retained by a call to get_nprocs(). I did not find an equivalent for the
number of threads in C. In C++, there would be
https://en.cppreference.com/w/cpp/thread/thread/hardware_concurrency, in
case it's relevant for anybody.
Also, add it to the cross-compilation pipeline
csiim_vars/csirs_vars used to be global array for each UE. Now its present
in phy_data which is in dynamically allocated memory.
MAC config was done without mutex while DL and UL threads could be running
at the same time.
get_ue_nas_info was allocating memory possibly from more than one thread.
Moved it into new init function for UE NAS layer.
Addreses most issues in #869
The goal of this MR is to improve readability, maintainability and consistency
of gNB initialization functions.
This MR is:
- cleaning up redundant and unused code
- refactoring init_gNB, l1_north_init_gNB, RCconfig_NR_L1, NRRCConfig
- removing redundant memory allocation for gNB RAN context and L1 instances
- cleaning up redundant log lines
telnetsrv uses the Intel/AMD-specific "cpuid" instruction, which is not
available on ARM machines. Remove the call.
The previous code was checking for the number of cores, which is
retained by a call to get_nprocs(). I did not find an equivalent for the
number of threads in C. In C++, there would be
https://en.cppreference.com/w/cpp/thread/thread/hardware_concurrency, in
case it's relevant for anybody.
the version in develop is difficult to understand, and surprizing design
it loops only when avx2mod == 0 because when this test is false, the
size is always small i also spent time to understand, but i think i have
not changed it by not looping over the array.
Use non-recursive polar decoder after traversing the tree once. Maximum number
of nodes is set to 600 (unsure of the maximum). This is more performant
than the recursive version.
- Ensure packed struct through bitfield
- decoder tree buffer increase: i don't find evidence in the 3GPP
standard of the max size of polar coded PDU. even with this max size,
the way this tree is built is not trivial. so, it is hard to predict,
i just put 8 system pages (32KB) that looks enough [1]
- a lot of reformatting
[1] https://arxiv.org/pdf/1804.04389
according to this paper, the largest polar code in 5G is in UL, so
likely the biggest problem will be in gNB, not the UE. in DL, the max
output coded block is 512, in UL 1024. probably the tree we discuss is
related to this size.
"frozen bits" means only bits we don't encode/decode because polar code
size is only by power of 2.
We see this in OAI code: NR_POLAR_PUCCH_N_MAX is 10, so 2^10 is 1024,
that is the maximum size for 5G polar code length. in the code, we
assert if N > 512: "N = %d, not done yet\n",
polarParams->N". so, the today OAI code can't do PUCCH large blocks.
using current oai limitation of 2⁹ max code size, we can create up to
2^9+2⁸... nodes, so 1023 nodes in the tree. the problem then is that
each node have variable size, depending on the 'level' (the power of 2
we are currently). the algo provision large alpha and beta to be able
to store all lower levels in the tree (int leaf_sz = 1 << level)
therefore upper tree nodes are large (the top level for n=9 uses about
1.5KB) and the bottom nodes uses 64 bytes. if all nodes are populated,
the size will be very large: 1.5KB + 2 * 800 + .... but, we create
nodes in the tree only for the "information bits", so the payload, that
is limited to 128 bits (else we assert, the code is not "finished").
1.5KB * 128 is >> 8KB i allocated. but, we can't create more than one
mode at top level, so there is maximum 1.5KB + 2 * 800, + 4 * 400 + 8 *
200 + 16 * 100 + remaining of 128-32 nodes of 64 bytes. about 14KB.
i allocated 1024*sizeof(__m256i) bytes = 32KB that looks good.
* the goal of this function is to initialize and configure the RAN Context
* the goal of get_options is to get command line options
* this commit aims at making the implementation more consistent
* move initialization of RC.nb_nr_CC to this function
* cleanup redundant initializations of RC.nb_nr_macrlc_inst outside NRRCConfig
* cleanup redundant initization of RC.nb_nr_macrlc_inst from getter function (get_node_type)
* cleanup RC initialization in RCconfig_NR_L1
* removed redundant log lines (print number of instances in NRRCConfig only)
* do RC init after getting CL options and configuration
* get_node_type shall access configuration only, not RC context
* NRRCConfig shall be called only once: made it thread-safe
* nb_nr_inst represents the number of gNB instances and the number of RAN contexts
* it used also to count the number of RRC instances in the node
* it is set from config file in NRRCConfig, therefore redundant checks after
this function have been removed
* redundant global variable NB_gNB_INST, set after nb_nr_inst, was removed
* gNB and L1 init is done in init_gNB and RCconfig_NR_L1
* moved RCconfig_nr_prs out of create_gNB_tasks for consistency
* do RCconfig_nr_prs only for L1 instances
* removed initialization of gNB
* separate function to get blacklisted UL PRBs
* call the getter in both L1 and MAC/RLC configuration
* other minor improvements
Jaroslava Fiedlerova