Age | Commit message (Collapse) | Author | Files | Lines |
|
Currently these algorithms modify other objects (MS, TBF, PDCH) even
if the allocation will fail later on. To implement an algorithm that
dynamically tries another algorithm on failure (e.g. A after B), the
first (failing) algorithm should not change or damage anything.
This commit refactors algorithm A and B to delay the actual allocation
until it is known that the allocation will not fail.
Ticket: #1934
Sponsored-by: On-Waves ehf
|
|
Currently this code path is only used, if an allocation has been
taken place in a former call to an allocation algorithm function.
If this was for an DL TBF, the first common TS was selected,
otherwise the least used common TS was selected for an UL TBF.
The shrinking of the UL set (to 1<<first_common_ts) is done in the
latter case.
This commit removes an additional code path that aligns the UL set to
first_common_ts, because it has no more influence on the set of
common TS after both UL and DL TBF have been allocated.
Sponsored-by: On-Waves ehf
|
|
Currently the TBFs are registered in a TFI indexed array within the TRX
objects. TBFs can be searched globally by TFI and TRX number. This
conflicts with the use of the same TFI for different TBF on different
PDCH. This use case requires the specification of the PDCH as
additional search dimension.
This commit moves the TFI index TBF arrays into the PDCH objects. The
related methods are updated accordingly.
Ticket: #1793
Sponsored-by: On-Waves ehf
|
|
Currently the TFI are managed per TRX, thus only a maximum of 32 TBF
per direction and per TRX are possible simultaneously.
This commit modifies algorithm_a() to allow the sharing of TFI
between different PDCH. Since algorithm A only assigns a single slot
to each TBF, the TFI of each PDCH can be assigned independently.
This increases the maximum to 32 TBF per direction and per PDCH
concerning the TFI allocation.
Ticket: #1793
Sponsored-by: On-Waves ehf
|
|
Currently the TFI and the TRX have to be determined before the actual TBF
allocation function is called, passing TFI and TRX number as
parameters. This does fit to TFI reuse for different slots, since
this were tightly coupled with the slot selection.
This commit just moves the TFI selection into the alloc_algorithm
functions. The tfi parameter is removed from the the TFI alloc
functions. The trx parameter is changed into use_trx to optionally
limit the trx selection (same semantics like in tfi_find_free).
Sponsored-by: On-Waves ehf
|
|
Currently the handling of MS_B and MS_C is not compliant with TS
45.002, annex B.1. These values may only interpreted as 0, if
frequency hopping is not enabled and if there is no change from Rx to
Tx or vice-versa.
This commit sets Ttb/Trb to 1 if the table entry is MS_B/MS_C, since
only combined down/up access modes are supported.
Sponsored-by: On-Waves ehf
|
|
Currently the masks are computed equally for each class type. This
does not make much sense for class type 2 MS, since those are capable
to work in full duplex mode.
This commit sets the masks to 0xff for class type 2 MS.
Sponsored-by: On-Waves ehf
|
|
According to TS 45.002, 6.4.2.2 the choice whether Tta or Tra has to
be applied, depends on the medium access mode (currently always
dynamic) and the number of UL/DL slots. Currently either value can be
used which might result in combinations not covered by the spec.
This commit changes find_multi_slots() to skip non-compliant
combinations.
Note that this code will have to be extended, if other medium
access modes are implemented.
Sponsored-by: On-Waves ehf
|
|
The local enums MASK_TT and MASK_TR replace the hard coded indices.
The variable m_idx is renamed to mask_sel for more clarity.
Sponsored-by: On-Waves ehf
|
|
Both functions only differ in the computation of the value for
num_tbfs.
This commit merge both functions and adds a parameter containing a
function for that compuation.
Sponsored-by: On-Waves ehf
|
|
Currently the slot selection of algorithm A is based on the current
slot usage by active TBF. Especially in the Dl after UL case which
reflects the commen use case "MS initiates TCP connection", the
resulting distribution is not optimal with respect to PDCH usage.
This commit changes the implementation to use the slot reservation
information instead.
Sponsored-by: On-Waves ehf
|
|
The current logging statements within the inner loop of
find_multi_slots drain quite a lot of CPU resources even if
LOGL_DEBUG is not enabled. This might cause issues on the target
hardware.
This commit disables these LOGP calls unless the
ENABLE_TS_ALLOC_DEBUG macro has been set explicitly. This results in
a reduction in the CPU usage reported by callgrind for
find_multi_slots from 42% to 25% when executing AllocTest.
Sponsored-by: On-Waves ehf
|
|
According to callgrind, this function consumes 33% CPU when running
the AllocTest program.
This commit uses the assigned_usf() method to get the USFs allocated
by a PDCH instead of traversing the TBFs.
Sponsored-by: On-Waves ehf
|
|
Currently the search of the "best" slot combination is done
separately from the UL slot selection, which can lead to an
allocation failure due to USF exhaustion even if another combination
had been possible.
This commit reduces the probability for this event by skipping UL
slots without free USF while calculation the capacity.
Note that the implementation is rather inefficient which will be
fixed by the following commits.
Sponsored-by: On-Waves ehf
|
|
Since currently the algorithm B will only allocate a single UL slot
and will have to stick to it (first common TS), the other possible UL
slots will not be allocated while the reservation is kept.
This commit adds code to update the reserved set of UL slots to only
reserve the single common TS when the UL TBF is allocated.
Interestingly this leads to fewer allocated TBF in some cases due to
USF exhaustion. This will be improved by the following commit "alloc:
Skip common TS without free USF".
Sponsored-by: On-Waves ehf
|
|
Currently the capacity of a PDCH slot is calculated as 32 - N_reserved
for each direction. This can result in a capacity of 0 and even
negative values.
This commit forces the capacity of an usable slot to be at least zero
under the assumption, that an overly reserved PDCH is still better
than none.
Sponsored-by: On-Waves ehf
|
|
Currently al possible UL slots are included in the capacity
calculation which is the base of the slot selection. Nevertheless
UL-only slots will never be used, since only one uplink slot (which
must be a common slot) will be used.
This patch changes the code to only include common slots in the
capacity sum.
Note that this might not be optimal if algorithm B supported
multiple uplink slots.
Sponsored-by: On-Waves ehf
|
|
The current implementation always starts the downlink slot allocation
with the first possible slot, depending on which channels are enabled
and which multislot class is offered by the MS. So in configurations
with many (>4) PDCH, some PDCH are not really used.
The new implementation introduced by this commit differs as follows:
- The reservation mechanism provided by GprsMs is used to avoid
incompatibilities is used in the same way like algo A does. This
basically means, that the allocation is done once when the first
TBF is requested and then used until all TBF have been released.
- All combinations of Rx and Tx slots are checked for compatibility
with the multiscot class. Basically the combination with the most
usable PDCH and the least number of reservations is used.
- Only one UL slots is provided.
- Tta and Tra are checked.
Sponsored-by: On-Waves ehf
|
|
Currently algorithm A bases its time slots selection on the number of
TBF actively using the PDCHs. This statistically prefers the first
time slots, especially with short living TBFs. So when the first TBF
is triggered by an uplink transfer (which generally results in a
short-lived TBF) the potentially longer living DL TBF will be bound
to the same slot. When another MS then requests an uplink TBF, it
will get the same slot (no UL TBF currently active).
This commit changes the algorithm to base its selection on reserved
slots instead.
Sponsored-by: On-Waves ehf
|
|
According to TS 45.002, 6.4.2 the training sequence (TSC) must be the
same for all slots in a multi-slot set.
This commit updates find_possible_pdchs() to only consider slots with
the same TSC if more that 1 slot shall be assigned.
Note that the first PDCH's TSC will be used as reference, so if two
or more groups with a common TSC are configured, only the first will
be used. This restriction does not apply to algorithm A, since it
will not assign more than one slot and therefore sets the max_slots
parameter to 1.
Sponsored-by: On-Waves ehf
|
|
Currently only the first enabled PDCH will be used. Beside the
throughput this will also limit the number of TBFs:
- number of UL TBFs <= 7
- number of DL TBFs <= 32
This commit changes the allocation algorithm to use the PDCH with the
least number of attached TBFs. This will improve the troughput in
both directions and the UL limits:
- number of UL TBFs <= min(32, N_PDCH * 7) UL TBFs
Ticket: #1794
Sponsored-by: On-Waves ehf
|
|
Currently the PDCH object do not know anything about the TBFs using
them. To make the slot allocation load dependant, at least some
numbers are required.
This commit adds TBF counters (one per direction) and the related methods
attach_tbf, detach_tbf, and num_tbfs to gprs_rlcmac_pdch.
Sponsored-by: On-Waves ehf
|
|
Currently the old TBF (either uplink or downlink) is passed around at
TBF allocation mainly to get information about the MS. To implement
more complex allocation algorithms, the MS object itself will be
needed anyway.
This commit replaces the old_tbf arguments by MS object arguments.
Sponsored-by: On-Waves ehf
|
|
The ms_class value is a property of the MS and thus belongs to the
GprsMs class. Nevertheless the MS object is created after the TLLI
gets known, so the value still has to be stored in the TBF initially.
This commit add the ms_class value to the GprsMs class and introduces
TBF accessor functions which either access that object or, if that is
not available, the value stored locally.
Ticket: #1674
Sponsored-by: On-Waves ehf
|
|
There is no need for the union/struct anymore. Make the variable members
of the UL/DL class.
As a result gprs_rlc_dl_window gets a reset() method because
memset(&dir.dl, 0, sizeof(dir.dl)) doesn't work anymore in reuse_tbf().
Ticket: SYS#389
Sponsored by: On-Waves ehf
|
|
Use UL/DL TBFs instead of the base class wherever it is clear that the
code only deals with one kind of TBF.
Ticket: SYS#389
Sponsored by: On-Waves ehf
|
|
The current code keeps a reference to all tbfs in the bts and another
reference in the pdch. This allows for the possibility of both lists to
go out of sync.
This patch removes the pdch-specific list of ul and dl tbfs and uses the
lists in the bts to lookup tbfs everywhere.
Performance for going through the global list is not an issue yet. We
can optimize this later and in a better way.
Sponsored-by: On-Waves ehf
|
|
The current code would only ever assign one PDCH for the initial
assignment (from CCCH). Only if reuse_tbf is called the algorithm would
actually use multiple DL PDCHs if possible.
This patch introduced a tbf attribute upgrade_to_multislot that is set
if we have multiple PDCH configured, and support multislot assignment,
but can only assign a single PDCH (alloc_algorithm_b, parameter single
is set). In this case after the assignment completes (and the MS is
listening on a PDCH) we resend a DL assignment though the PACCH and this
time we can assign multiple timeslots.
|
|
Counter j must be wrapped to prevent beeing negative, when it is
initialized. This wrapping happens, if TS 0 is used for PDCH in
combination with regular GPRS phones (MS class 12 or similar).
|
|
|
|
After reduce_rx_window() and update_rx_win_max() was called, one or more TS
might be removed. tx_win_min and tx_win_max must be adjusted to the new range
of allocated slots.
|
|
|
|
In order to poll MS, the mobile must be able to receive polling request.
In order to allow the MS to transmit, the USF must be received by the mobile.
|
|
|
|
The algorithm does not support more than 5 TS on downlink for type 1 MS.
Supporting more than 5 TS would require adding more complexity to this
algorithm. MS that support more than 4 (or 5) TS on downlink are rare,
if they really exist.
|
|
|
|
Create a select_ul_slots which is very (95%) similar to the
select_dl_slots handling. This needs to be refactored and the
todo for multiple uplink slots should be handled too.
Add a warning about a potential failure on a busy PCU.
|
|
|
|
|
|
|
|
The naming of RX/TX still looks fishy and it should use DL/UL instead.
Work on pointers right now. We could introduce a struct with the window
min and max and pass this struct. The usage of 'D' appears wrong in the
ul_usage..
|
|
This code could evolve into working for Uplink and Downlink. The
only different for the final Uplink assignment is that free USFs
are collected.
|
|
Put the cases for MS_A/MS_B and MS_A/MS_C together.
|
|
It looks like the code is different (without a reason) a good
reason.
|
|
We can just use first_ts and the trx/pdch to extract this information.
Avoid duplication of data.
|
|
All logging code that used tbf->tfi is now using tbf_name to
print the the TBF. External code is now using tfi() which is
inlined and should result in the same code being generated as
before (+debug code that can be stripped).
|
|
|
|
|
|
The list belongs to the BTS. This makes cleaning this up more easy
and establishes a hierachy of resources that start from the BTS. The
debug_diagram code is now broken.
|
|
When a PDCH is disabled all resources should be freed. This is
currently not possible as the PDCH does not know where it belongs
to. On top of that the list (and other resources) should be
properly initialized on construction so that disable() is idempotent
and does not check if it was disabled. During the re-factoring I
noticed that during a sysmobts re-start some resources are not
freed. I left a warning in the code to resolve this issue later.
|