cache: fix large answers from packet cache

Atomic packets larger than both 4k and net.bufsize() could not be fetched from cache; now that's fixed in a minimalistic way. (Minimalistic except for nitpicks like adding comments.)

added 1 commit

• 8f794aaf - cache: fix large answers from packet cache

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This crash will need some investigation https://gitlab.labs.nic.cz/knot/knot-resolver/-/jobs/375676#L717

marked as a Work In Progress

changed the description

added bug performance labels

Seems reproducible. 2/2 runs of this job crashed. (No others did, though.)

added 1 commit

• d52b1bf0 - cache: fix large answers from packet cache

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unmarked as a Work In Progress

Fix of that crash seems confirmed by repeated runs of the CI jobs.

3-fold respdiff is running to make sure we are not missing something: https://gitlab.labs.nic.cz/knot/knot-resolver/pipelines/62209

added 4 commits

• d52b1bf0...a9ff9b8a - 3 commits from branch master
• 2c702ca1 - cache: fix large answers from packet cache

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merged

mentioned in commit 24631612

Respdiff data were quite noisy but as far as I can tell by manual inspection it is okay.

I also checked them.