I’m afraid the problem is present even with 6.3.1 linux kernel. So it seems GHC 9.4 is the only way.
Why wouldn’t the fix be backported to 9.2 though?
Funnily, this issue did get worse with newer kernels.
Btw, can someone confirm that adding +RTS -xp -RTS (or export GHCRTS='-xp') actually fixes the problem (or makes it much more unlikely)?