[Ovmsdev] ESP32/3 benchmark (was: External Wifi antenna)

[Craig Leres]

On 3/14/21 12:15 AM, Michael Balzer wrote:
> you triggered the watchdog by pasting all commands into the shell, you 
> need to leave 1-2 seconds between the commands to feed the dog.

I didn't realize that was possible!

Do persistent metrics impact test mode 2? Looking at the ESP32-WROVER 
dat sheet (version 2.4) I see:

     ESP32-D0WDQ6 contains two low-power Xtensa 32-bit LX6
     microprocessors. The internal memory includes:

      - 448 KB of ROM for booting and core functions.

      - 520 KB of on-chip SRAM for data and instructions.

      - 8 KB of SRAM in RTC, which is called RTC FAST Memory and can
        be used for data storage; it is accessed by the main CPU
        during RTC Boot from the Deep-sleep mode.

      - 8 KB of SRAM in RTC, which is called RTC SLOW Memory and can
        be accessed by the co-processor during the Deep-sleep mode.

      - 1 Kbit of eFuse: 256 bits are used for the system (MAC address
        and chip configuration) and the remaining 768 bits are
        reserved for customer applications, including flash-encryption
        and chip-ID.

And:

     3.2 External Flash and SRAM

     SP32-WROVER integrates a 4 MB of external SPI flash and an 8
     MB PSRAM for more memory space.

It's confusing to me that the external ram is interchangeably called 
PSRAM (pseudo static RAM), SPI SRAM, and SPIRAM.

Anyway, does test mode 2 only access SPIRAM or does it also pull from 
RTC slow memory?

> Your results could indicate the SPIRAM workaround doesn't really degrade 
> performance for the kind of RAM accesses the test does.
> 
> Or it indicates something's wrong in your build / configuration, i.e. 
> the SPIRAM workaround is still in place.
> 
> Ideas:
> 
> a) Did you do a "make clean" after disabling the SPIRAM workaround?

I've had the workaround disabled ever since I upgraded my modules to V3 
and I don't bother with "make clean", I usually use "rm -rf build" (!)

> b) Verify your toolkit version (should be crosstool-ng-1.22.0-97-gc752ad5)

ice 1243 % xtensa-esp32-elf-gcc --version
xtensa-esp32-elf-gcc (crosstool-NG crosstool-ng-1.22.0-97-gc752ad5) 5.2.0

> c) Verify the actual compiler & linker options given by doing "make -n"

I did something like:

     rm -rf build ; gmake -n | fgrep esp32can.o | fmt -1 > file

with CONFIG_SPIRAM_CACHE_WORKAROUND enabled and disabled and it looks 
like the flag is present/flag:

     ice 1277 % diff /tmp/workaround.txt /tmp/noworkaround.txt
     21d20
     < -mfix-esp32-psram-cache-issue

So my setup looks correct to me.

		Craig