[Ovmsdev] OVMS Poller module/singleton

Michael Geddes frog at bunyip.wheelycreek.net
Fri Jun 14 14:31:14 HKT 2024


Was this all good?  I want to make sure I get to the bottom of this whole
issue asap!

https://github.com/openvehicles/Open-Vehicle-Monitoring-System-3/pull/1018

Was there something else you needed me to work on to make sure this all
works for all supported cars?

//.ichael

On Sun, 26 May 2024 at 21:15, Michael Balzer via OvmsDev <
ovmsdev at lists.openvehicles.com> wrote:

> OK, I see now why it wouldn't send the notification: the V2 & V3 server
> register for notifications up to COMMAND_RESULT_NORMAL = 1024 characters.
>
> The report quickly becomes larger than 1024 characters, so the
> notifications no longer get sent via the server connectors.
>
> You need to either reduce the size, split the report, or use data
> notifications instead.
>
> On the reset value init: for my float targeting smoothing helper class for
> the UpMiiGo, I implemented a gradual ramp up from 1 to the requested sample
> size. You can do something similar also with powers of 2. IOW, yes,
> initialization from the first values received is perfectly OK.
>
> Regards,
> Michael
>
>
> Am 26.05.24 um 14:35 schrieb Michael Geddes:
>
> It _*should*_ already be sending a report on charge stop.
>
> MyEvents.RegisterEvent(TAG, "vehicle.charge.stop",
> std::bind(&OvmsPollers::VehicleChargeStop, this, _1, _2));
>
> Reset on charge start/vehicle on is a good idea.
>
> A question – would it be silly if the first value after a reset, rather
> than using 0 average to start with, if the average got set to the initial
> value?  I’m in 2 minds about it. It would make the average more useful
> quicker.
>
> //.ichael
>
> On Sun, 26 May 2024, 19:39 Michael Balzer via OvmsDev, <
> ovmsdev at lists.openvehicles.com> wrote:
>
> As the averages quickly decline when idle, an automatic report should
> probably also be sent on charge stop.
>
> Also, I think you should automatically reset the timer statistics on drive
> & charge start.
>
> First stats from charging my UpMiiGo:
>
> Type           | count  | Utlztn | Time
>                | per s  | [‰]    | [ms]
> ---------------+--------+--------+---------
> Poll:PRI    Avg|    1.00|   0.723|    0.716
>            Peak|        |   1.282|    3.822
> ---------------+--------+--------+---------
> Poll:SRX    Avg|    7.72|   1.246|    0.184
>            Peak|        |   3.128|    1.058
> ---------------+--------+--------+---------
> RxCan1[7ae] Avg|    2.48|   0.915|    0.362
>            Peak|        |   1.217|    1.661
> ---------------+--------+--------+---------
> RxCan1[7cf] Avg|    4.76|   1.928|    0.397
>            Peak|        |   2.317|    2.687
> ---------------+--------+--------+---------
> RxCan1[7ed] Avg|    3.38|   1.251|    0.327
>            Peak|        |   8.154|   12.273
> ---------------+--------+--------+---------
> RxCan1[7ee] Avg|    0.21|   0.066|    0.297
>            Peak|        |   0.225|    1.690
> ---------------+--------+--------+---------
> TxCan1[744] Avg|    1.49|   0.022|    0.011
>            Peak|        |   0.032|    0.095
> ---------------+--------+--------+---------
> TxCan1[765] Avg|    3.89|   0.134|    0.027
>            Peak|        |   0.155|    0.113
> ---------------+--------+--------+---------
> TxCan1[7e5] Avg|    2.32|   0.038|    0.013
>            Peak|        |   0.295|    0.084
> ---------------+--------+--------+---------
> TxCan1[7e6] Avg|     1  0.21|   0.002|    0.008
>            Peak|        |   0.010|    0.041
> ---------------+--------+--------+---------
> Cmd:State   Avg|    0.00|   0.000|    0.007
>            Peak|        |   0.005|    0.072
> ===============+========+========+=========
>       Total Avg|   27.46|   6.324|    2.349
>
>
> Overall healthy I'd say, but let's see how it compares.
>
> 7ed is the BMS, the peak time is probably related to the extended cell
> data logging -- I've enabled log intervals for both cell voltages &
> temperatures.
>
> Regards,
> Michael
>
> Am 26.05.24 um 08:42 schrieb Michael Balzer via OvmsDev:
>
> The notification works on my devices, it only has a garbled per mille
> character -- see attached screenshot. The same applies to the mail version:
>
>
> Poller timing is: on
>
> Type           | count  | Utlztn | Time
>
>                | per s  | [‰]    | [ms]
>
> ---------------+--------+--------+---------
>
> Poll:PRI    Avg|    0.25|   0.119|    0.382
>
>            Peak|        |   0.513|    0.678
>
> ---------------+--------+--------+---------
>
> RxCan1[597] Avg|    0.01|   0.004|    0.021
>
>            Peak|        |   0.000|    0.338
>
> ---------------+--------+--------+---------
>
> RxCan1[59b] Avg|    0.01|   0.011|    0.053
>
>            Peak|        |   0.000|    0.848
>
> ---------------+--------+--------+---------
>
> Cmd:State   Avg|    0.01|   0.002|    0.012
>
>            Peak|        |   0.000|    0.120
>
> ===============+========+========+=========
>
>       Total Avg|    0.28|   0.135|    0.468
>
>
> The encoding is a general issue. The character encoding for text messages
> via V2/MP is quite old & clumsy, it's got an issue with the degree celcius
> character as well. We previously tried to keep all text messages within the
> SMS safe character set (which e.g. lead to writing just "C" instead of
> "°C"). I'd say we should head towards UTF-8 now. If we ever refit SMS
> support, we can recode on the fly.
>
> Regarding not seeing the notification on your phone:
>
> a) Check your notification subtype/channel filters on the module. See
> https://docs.openvehicles.com/en/latest/userguide/notifications.html#suppress-notifications
>
> b) Check your notification vehicle filters on the phone (menu on
> notification tab): if you enabled the vehicle filter, it will add the
> messages of not currently selected vehicles to the list only, but not raise
> a system notification. (Applies to the Android App, no idea about the iOS
> version)
>
> Regards,
> Michael
>
> Am 26.05.24 um 06:32 schrieb Michael Geddes:
>
> Hi,
>
>
>
> I'm trying to finalise this now .. and one last thing is that I don't get
> the report coming to my mobile. I'm using the command:
>
>   MyNotify.NotifyString("info", "poller.report", buf.c_str());
>
>
>
> Where the buffer string is just the same as the report output.  Should I
> be using some other format or command?
>
> I get "alert" types (like the ioniq5 door-open alert) fine to my mobile.
>
>
>
> Michael.
>
>
>
> On Sun, 19 May 2024, 12:51 Michael Balzer via OvmsDev, <
> ovmsdev at lists.openvehicles.com> wrote:
>
> A builtin web UI for this seems a bit over the top. Builtin web config
> pages should focus on user features, this is clearly a feature only needed
> during/for the development/extension of a vehicle adapter. Development
> features in the web UI are confusing for end users.
>
> If persistent enabling/disabling is done by a simple config command (e.g.
> "config set can poller.trace on"), that's also doable by users.
>
> Regards,
> Michael
>
> Am 19.05.24 um 02:06 schrieb Michael Geddes:
>
> I was so focused on how I calculated the value that I totally missed that
> ‰ would be a better description.  I could also use the  system 'Ratio'
> unit... so % or ‰.
>
>
>
> I'll make space to put 'Avg' on the row.  Was trying to limit the width
> for output on a mobile.  I agree it would make it easier to understand.
>
> Totals also makes sense.
>
>
>
> Should I make this a configuration that can be set on the web-page?   I'd
> probably use a configuration change notification so that the very bit
> setting is sync'd with the 'configuration' value.
>
>
>
> //.ichael
>
>
>
> On Sat, 18 May 2024, 14:05 Michael Balzer, <dexter at expeedo.de> wrote:
>
> I'm not sure whether the 'max' should be the maximum of the smoothed
> value.. or the maximum of the raw value.
>
>
> It should normally be the maximum of the raw value I think, the maximum of
> the smoothed value cannot tell about how bad the processing of an ID can
> become.
>
> The naming in the table is a bit confusing I think. (besides: I've never
> seen "ave" as the abbreviation for average)
>
> If I understand you correctly, "time ms per s" is the time share in per
> mille, so something in that direction would be more clear, and "length ms"
> would then be "time [ms]".
>
> The totals for all averages in the table foot would also be nice.
>
> Maybe "Ave" (or avg?) also should be placed on the left, as the "peak"
> label now suggests being the peak of the average.
>
> Btw, keep in mind, not all "edge" users / testers are developers (e.g. the
> Twizy driver I'm in contact with), collecting stats feedback for vehicles
> from testers should be straight forward. Maybe add a data/history record,
> sent automatically on every drive/charge stop when the poller tracing is on?
>
> Regards,
> Michael
>
> Am 18.05.24 um 02:28 schrieb Michael Geddes:
>
> You did say max/pead value.  I also halved the N for both.
>
> I'm not sure whether the 'max' should be the maximum of the smoothed
> value.. or the maximum of the raw value.
>
> This is currently the raw-value maximum.
>
> The problem is that the middle column is the maximum of the {{sum over
> 10s} / (10*1000,000)
>
> I could easily change the 'period' to 1s and see how that goes.. was just
> trying to reduce the larger calculations.
>
>
>
>
>
> Usage: poller [pause|resume|status|times|trace]
>
>
> OVMS# poller time status
> Poller timing is: on
> Type         | Count    | Ave time  | Ave length
>              | per s    | ms per s  | ms
> -------------+----------+-----------+-----------
> Poll:PRI     |      1.00|      0.559|      0.543
>  peak        |          |      0.663|      1.528
> -------------+----------+-----------+-----------
> Poll:SRX     |      0.08|      0.009|      0.038
>  peak        |          |      0.068|      0.146
> -------------+----------+-----------+-----------
> CAN1 RX[778] |      0.11|      0.061|      0.280
>  peak        |          |      0.458|      1.046
> -------------+----------+-----------+-----------
> CAN1 RX[7a8] |      0.04|      0.024|      0.124
>  peak        |          |      0.160|      0.615
> -------------+----------+-----------+-----------
> CAN1 TX[770] |      0.05|      0.004|      0.016
>  peak        |          |      0.022|      0.102
> -------------+----------+-----------+-----------
> CAN1 TX[7a0] |      0.02|      0.002|      0.011
>  peak        |          |      0.010|      0.098
> -------------+----------+-----------+-----------
> CAN1 TX[7b3] |      0.01|      0.001|      0.006
>  peak        |          |      0.000|      0.099
> -------------+----------+-----------+-----------
> CAN1 TX[7e2] |      0.02|      0.002|      0.011
>  peak        |          |      0.010|      0.099
> -------------+----------+-----------+-----------
> CAN1 TX[7e4] |      0.08|      0.008|      0.048
>  peak        |          |      0.049|      0.107
> -------------+----------+-----------+-----------
> Cmd:State    |      0.00|      0.000|      0.005
>  peak        |          |      0.000|      0.094
>
>
>
> On Fri, 17 May 2024 at 15:26, Michael Geddes <frog at bunyip.wheelycreek.net>
> wrote:
>
> This is what I have now.
>
> The one on the end is the one  MIchael B was after using an N of 32. (up
> for discussion).
>
>
>
> The middle is the time  spent in that even t per second.  It accumulates
> times (in microseconds), and then every 10s it stores it as smoothed (N=16)
> value.
>
> The Count is similar (except that we store a value of '100' as 1 event so
> it can be still integers and has 2 decimal places).
>
>
>
> Every received poll  does a 64bit difference to 32bit (for the elapsed
> time) and 64bit comparison (for end-of-period).
>
> It also does 1x 32bit smoothing and 2x 32bit adds.
>
>
>
> Then at the end of a 10s period, it will do a 64bit add to get the next
> end-of-period value, as well as the 2x 32bit smoothing calcs.
>
>
>
> This is from the Ioniq 5 so not any big values yet.  You can certainly see
> how insignificant the TX callbacks are.
>
> I'll leave it on for when the car is moving and gets some faster polling.
>
>
>
> OVMS# poll time status
> Poller timing is: on
> Type         | Count    | Ave time  | Ave Length
>              | per s    | ms per s  | ms
> -------------+----------+-----------+-----------
> Poll:PRI     |      1.00|      0.540|      0.539
> Poll:SRX     |      0.03|      0.004|      0.017
> CAN1 RX[778] |      0.06|      0.042|      0.175
> CAN1 TX[770] |      0.04|      0.002|      0.008
> Cmd:State    |      0.01|      0.001|      0.005
>
>
>
> ----------------------8<--------------------------------
>
>
>
> Nice smoothing class (forces N as a power of 2):
>
>   constexpr unsigned floorlog2(unsigned x)
>     {
>     return x == 1 ? 0 : 1+floorlog2(x >> 1);
>     }
>   /* Maintain a smoothed average using shifts for division.
>    * T should be an integer type
>    * N needs to be a power of 2
>    */
>   template <typename T, unsigned N>
>   class average_util_t
>     {
>     private:
>       T m_ave;
>     public:
>       average_util_t() : m_ave(0) {}
>       static const uint8_t _BITS = floorlog2(N);
>       void add( T val)
>         {
>         static_assert(N == (1 << _BITS), "N must be a power of 2");
>         m_ave = (((N-1) * m_ave) + val) >> _BITS;
>         }
>       T get() { return m_ave; }
>       operator T() { return m_ave; }
>     };
>
>
>
>
>
>
>
> On Thu, 16 May 2024 at 10:29, Michael Geddes <frog at bunyip.wheelycreek.net>
> wrote:
>
> Thanks Michael,
>
>
>
> My calculations give me ((2^32)-1) / (1000*1000*3600) = only 1.2 hours of
> processing time in 32bit.  The initial subtraction is 64bit anyway and I
> can't see a further 64bit addition being a problem. I have the calculations
> being performed in doubles at print-out where performance is not really an
> issue anyway. (Though apparently doing 64 bit division is worse than
> floating point).
>
>
>
> In addition
>
> * I currently have this being able to be turned on and off and reset
> manually (only do it when required).
>
>
>
> *  For the lower volume commands, the smoothed average is not going to be
> useful - the count is more interesting for different reasons.
>
>
>
> * The total time is quite useful. Ie a high average time doesn't matter if
> the count is low.  The things that are affecting performance are stuff with
> high total time. Stuff which is happening 100 times a second needs to be a
> much lower average than once a second.
>
>
>
> * A measure like 'time per minute/second' and possibly count per
> minute/seconds as a smoothed average would potentially be more useful. (or
> in addition?)
>
> I think we could do _that_ in a reasonably efficient manner using a 64 bit
> 'last measured time', a 32 bit accumulated value and the stored 32 bit
> rolling average.
>
> It would boils down to some iterative (integer) sums and multiplications
> plus a divide by n ^ (time periods passed)  - which is a shift - and which
> can be optimised to '0' if 'time-periods-passed' is more than
> 32/(bits-per-n) - effectively limiting the number of iterations.
>
> The one issue I can see is that we need to calculate 'number of
> time-periods passed' which is a 64 bit subtraction followed by a 32 bit
> division (not optimisable to a simple shift).
>
>
>
> * I'm also happy to keep a rolling (32bit) average time.
>
>    Even if you assume averages in the 100ms, 32bit is going to happily
> support an N of 64 or even 128.
>
>    Am I right in thinking that the choice of N is highly dependent on
> frequency. For things happening 100 times per second, you might want an N
> like 128.. where things happening once per
>
>    second, you might want an N of 4 or 8.  The other things we keep track
> of in this manner we have a better idea of the frequency of the thing.
>
>
>
> How about we have (per record type):
>
>   * total count (since last reset?) (32 bit)
>
>   * smoothed average of time per instance (32 bit)
>
>
>
>   * ?xx? total accumulated time since last reset (64bit) ?? <-- with the
> below stats this is much less useful
>
>
>
>   * last-measured-time (64 bit)
>
>   * accumulated count since last time-period (16bit - but maybe 32bit
> anyway for byte alignment?)
>
>   * smoothed average of count per time-period (32bit)
>
>   * accumulated time since last time-period (32bit)
>
>   * smoothed average of time per time-period (32bit)
>
>
>
> It's possible to keep the
>
>
>
> Is this going to be too much per record type?  The number of 'records' we
> are keeping is quite low (so 10 to 20 maybe) - so it's not a huge memory
> burden.
>
>
>
> Thoughts?
>
>
>
> //.ichael
>
> On Thu, 16 May 2024 at 03:09, Michael Balzer via OvmsDev <
> ovmsdev at lists.openvehicles.com> wrote:
>
> esp_timer_get_time() is the right choice for precision timing.
>
> I'd say uint32 is enough though, even if counting microseconds that can
> hold a total of more than 71 hours of actual processing time. uint64 has a
> significant performance penalty, although I don't recall the overhead for
> simple additions.
>
> Also & more important, the average wouldn't be my main focus, but the
> maximum processing time seen per ID, which seems to be missing in your
> draft.
>
> Second thought on the average… the exact overall average really has a
> minor meaning, I'd rather see the current average, adapting to the current
> mode of operation (drive/charge/…). I suggest feeding the measurements to a
> low pass filter to get the smoothed average of the last n measurements.
> Pattern:
>
> runavg = ((N-1) * runavg + newval) / N
>
> By using a low power of 2 for N (e.g. 8 or 16), you can replace the
> division by a simple bit shift, and have enough headroom to use 32 bit
> integers.
>
> Regards,
> Michael
>
> Am 15.05.24 um 06:51 schrieb Michael Geddes via OvmsDev:
>
> Formatting aside, I have implemented what I think Michael B was
> suggesting.  This is a sample run on the Ioniq 5 (which doesn't have
> unsolicited RX events).
>
>
>
> This uses the call esp_timer_get_time() got get a 64bit *microseconds*
> since started value - and works out the time to execute that way. It's
> looking at absolute time and not time in the Task - so other things going
> on at the same time in other tasks will have an effect.  (The normal tick
> count doesn't have nearly enough resolution to be useful - any other ideas
> on measurement?) I've got total accumulated time displaying in seconds and
> the average in milliseconds currently - but I can change that easy enough.
>
> The cumulative time is stored as uint64_t which will be plenty, as 32bit
> wouldn't be nearly enough.
>
>
>
> OVMS# *poller time on*
> Poller timing is now on
>
>
>
> OVMS# *poller time status*
> Poller timing is: on
> Poll [PRI]               : n=390 tot=0.2s ave=0.586ms
> Poll [SRX]               : n=316 tot=0.1s ave=0.196ms
> CAN1 RX[0778]            : n=382 tot=0.2s ave=0.615ms
> CAN1 RX[07a8]            : n=48 tot=0.0s ave=0.510ms
> CAN1 RX[07bb]            : n=162 tot=0.1s ave=0.519ms
> CAN1 RX[07ce]            : n=33 tot=0.0s ave=0.469ms
> CAN1 RX[07ea]            : n=408 tot=0.2s ave=0.467ms
> CAN1 RX[07ec]            : n=486 tot=0.2s ave=0.477ms
> CAN3 RX[07df]            : n=769 tot=0.2s ave=0.261ms
> CAN1 TX[0770]            : n=191 tot=0.0s ave=0.054ms
> CAN1 TX[07a0]            : n=16 tot=0.0s ave=0.047ms
> CAN1 TX[07b3]            : n=31 tot=0.0s ave=0.069ms
> CAN1 TX[07c6]            : n=11 tot=0.0s ave=0.044ms
> CAN1 TX[07e2]            : n=82 tot=0.0s ave=0.067ms
> CAN1 TX[07e4]            : n=54 tot=0.0s ave=0.044ms
> Set State                : n=7 tot=0.0s ave=0.104ms
>
> This is probably going to be quite useful in general!  The TX call-backs
> don't seem to be significant here. (oh, I should probably implement a reset
> of the values too).
>
>
>
> //.ichael
>
>
>
> On Sun, 12 May 2024 at 22:58, Michael Geddes <frog at bunyip.wheelycreek.net>
> wrote:
>
> Yeah - I certainly wasn't going to put a hard limit. Just a log above a
> certain time, that being said, the idea of just collecting stats (being
> able to turn it on via a  "poller timer" set of commands) would be much
> more useful.  I'll look into that.
>
>
>
> Average time is probably a good stat - and certainly what we care about.
>
>
>
> I actually am hopeful that those couple of things I did might help reduce
> that average time quite a bit (that short-cutting the isotp protocol
> handling especially).
>
>
>
> That p/r with logging changes might help reduce the unproductive log time
> further, but also makes it possible to turn on the poller logging without
> the RX task logs kicking in.
>
>
>
> //.ichael
>
>
>
>
>
> On Sun, 12 May 2024 at 22:29, Michael Balzer via OvmsDev <
> ovmsdev at lists.openvehicles.com> wrote:
>
> Warning / gathering debug statistics about slow processing can be helpful,
> but there must not be a hard limit. Frame/poll response processing may need
> disk or network I/O, and the vehicle task may be starving from punctual
> high loads on higher priority tasks (e.g. networking) or by needing to wait
> for some semaphore -- that's outside the application's control, and must
> not lead to termination/recreation of the task (in case you're heading
> towards that direction).
>
> I have no idea how much processing time the current vehicles actually need
> in their respective worst cases. Your draft is probably too lax, poll
> responses and frames normally need to be processed much faster. I'd say 10
> ms is already too slow, but any wait for a queue/semaphore will already
> mean at least 10 ms (FreeRTOS tick). Probably best to begin with just
> collecting stats.
>
> Btw, to help in narrowing down the actual problem case, the profiler could
> collect max times per RX message ID.
>
> Regards,
> Michael
>
> Am 12.05.24 um 10:41 schrieb Michael Geddes:
>
> I have a question for Michael B  (or whoever) - I have a commit lined up
> that would add a bit of a time check to the poller loop. What do we expect
> the maximum time to execute a poller loop command should be?
>
> This is a rough idea (in ms) I have.. based on nothing much really, so any
> ideas would be appreciated:
>
>     int TardyMaxTime_ms(OvmsPoller::OvmsPollEntryType entry_type)
>       {
>       switch (entry_type)
>         {
>         case OvmsPoller::OvmsPollEntryType::Poll: return 80;
>         case OvmsPoller::OvmsPollEntryType::FrameRx: return 30;
>         case OvmsPoller::OvmsPollEntryType::FrameTx: return 20;
>         case OvmsPoller::OvmsPollEntryType::Command: return 10;
>         case OvmsPoller::OvmsPollEntryType::PollState: return 15;
>         default: return 80;
>         }
>       }
>
>
>
> //.ichael
>
>
>
> On Mon, 6 May 2024 at 07:45, Michael Geddes <frog at bunyip.wheelycreek.net>
> wrote:
>
> I realise that I was only using the standard cable to test - which
> probably is not sufficient - I haven't looked closely at how the Leaf OBD
> to Db9 cable is different from standard.
>
>
>
> Ah, my bad out the queue length.   We are definitely queueing more
> messages though.   From my log of when the overflow happened, the poller
> was in state 0 which means OFF - ie nothing was being sent!!
>
>
>
> I'll look at the TX message thing - opt in sounds good - though it
> shouldn't be playing that much of a part here as the TXs are infrequent in
> this case (or zero when the leaf is off or driving) - On the ioniq 5 when
> I'm using the HUD - I'm polling quite frequently - multiple times per
> second and that seems to be fine!.
>
>
>
> I did find an issue with the throttling .. but  it would still mostly
> apply the throttling where it matters, so again, it shouldn't be the
> problem (also, we aren't transmitting in the leaf case).
>
>
>
> The change I made to the logging of RX messages showed how many in a row
> were dropped... and it was mostly 1 only in a run - which means even if it
> is a short time between - that means that the drops are being interleaved
> by at least one success!
>
>
>
> Sooo.. I'm still wondering what is going on.  Some things I'm going to try:
>
>
>
> * If the number of messages on the Can bus (coming in through RX) means
> that the queue is slowly getting longer and not quite catching up, then
> making the queue longer will help it last longer... but only pushes the
> problem down the road.
>
>   - Add 'current queue length' to the poller status  information to see if
> this is indeed the case?
>
>   - Add some kind of alert when the queue reaches a % full?
>
> * Once you start overflowing and getting overflow log messages, I wonder
> if this is then contributing to the problem.
>
>   - Push the overflow logging into Poller Task which can look at how many
> drops occurred since last received item.
>
> * Split up the flags for the poller messages into 2:
>
>    - Messages that are/could be happening in the TX/RX tasks
>
>    - Other noisy messages that always happen in the poller task.
>
>
>
> Thoughts on what else we might measure to figure out what is going on?
>
>
>
> //.ichael
>
>
>
>
>
> On Sun, 5 May 2024, 19:29 Michael Balzer via OvmsDev, <
> ovmsdev at lists.openvehicles.com> wrote:
>
> Michael,
>
> the queue size isn't in bytes, it's in messages:
>
>
>  * @param uxQueueLength The maximum number of items that the queue can
> contain.
>  *
>  * @param uxItemSize The number of bytes each item in the queue will
> require.
>
>
> Also, from the time stamps in Dereks log excerpt, there were quite some
> dropped frames in that time window -- at least 23 frames in 40 ms, that's
> bad.
>
> Queue sizes are currently:
>
> CONFIG_OVMS_HW_CAN_RX_QUEUE_SIZE=60
> CONFIG_OVMS_VEHICLE_CAN_RX_QUEUE_SIZE=60
>
> The new poller now channels all TX callbacks through the task queue
> additionally to RX and commands. So setting the queue size to be larger
> than the CAN RX queue size seems appropriate.
>
> Nevertheless, an overflow with more than 60 waiting messages still
> indicates some too long processing time in the vehicle task.
>
> TX callbacks previously were done directly in the CAN context, and no
> current vehicle overrides the empty default handler, so this imposed almost
> no additional overhead. By requiring a queue entry for each TX callback,
> this feature now has a potentially high impact for all vehicles. If passing
> these to the task is actually necessary, it needs to become an opt-in
> feature, so only vehicles subscribing to the callback actually need to cope
> with that additional load & potential processing delays involved.
>
> Regards,
> Michael
>
>
>
> --
> Michael Balzer * Helkenberger Weg 9 * D-58256 Ennepetal
> Fon 02333 / 833 5735 * Handy 0176 / 206 989 26
>
> _______________________________________________
> OvmsDev mailing list
> OvmsDev at lists.openvehicles.com
> http://lists.openvehicles.com/mailman/listinfo/ovmsdev
>
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