RTS does not emit ticky counter samples into eventlog (#19054) · Issues · Glasgow Haskell Compiler / GHC

RTS does not emit ticky counter samples into eventlog

RTS does not emit ticky counter samples into eventlog when compiled and linked with necessary flags.

I discovered this issue while working on nofib#10

Compile a hello-world program with

ghc -eventlog -ticky -ticky-allocd -ticky-dyn-thunk -rtsopts HelloWorld.hs --make -fforce-recomp

then run it

./HelloWorld +RTS -lT

check the eventlog

ghc-events show HelloWorld.eventlog

Observe that event 211 EVENT_TICKY_COUNTER_SAMPLE is missing in the eventlog.

EVENT_TICKY_COUNTER_SAMPLE is present in the eventlog.