mdns component high static resource usage

[projectgus]

Answers checklist.

• I have read the documentation for esp-protocols components and the issue is not addressed there.
• I have updated my esp-protocols branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

Hi @david-cermak, hope you're doing well!

I don't know if this is an actionable request, but MicroPython has been using the mdns component v1.1.0 for a long time (oops!) Today I went to update it to the latest v1.11.3 to pick up a bug fix.

Our binary size report indicated this update would add 7452 bytes of flash size and just over 2KB more static RAM usage! The RAM usage in particular is a big concern for us on smaller chips.

We're using the same set of mDNS features before and after the update, so I was wondering if there might please be any config options that could be added to this component to disable some resource-heavy features and reclaim some flash size and static RAM?

(Context from MicroPython side: micropython/micropython#19468 - we've temporarily compromised by updating only to v1.3.2 which adds 5000 bytes of binary size but no extra static RAM.)

[david-cermak]

Hi Angus,
Nice to hear from you 👋
Thanks for the report, checking the sizes with IDF tools ( libmdns.a: esp_idf_size --archives) I'm getting:

tag	.text	.rodata	flash	.data	.bss	DRAM
1.1.0	26664	84	26796	48	1910	1958
1.3.2	30899	84	31031	48	1910	1958
1.9.0	30159	182	30389	48	2254	2302
1.10.0	31047	912	32007	48	2354	2402
1.11.0	31494	901	32443	48	2354	2402
1.11.3	33246	1047	34341	48	2354	2402

Which is in line with your report of flash size increase +7452, but don't see the +2K of static ram (just bss ~+456)
Isn't it possible that the data delta in micropython's elf also include some flash rodata (not only .dram0.data)? (there was a big refactor in v1.11 splitting the monolithic mdns.c into multiple modules, explaining the increase with debug/error log strings)

I was wondering if there might please be any config options

Yes, we can add CONFIG_MDNS_ENABLE_BROWSE to opt out the browse feature (~3/4 KB flash)
And probably also use dynamic task create when SPIRAM task alloc is off (~340 BSS)