wiki:Commentary/Profiling/TickyNotes

Version 1 (modified by kirsten, 7 years ago) (diff)

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Kirsten's sketchy notes on getting ticky to work

Macros for bumping ticky counters are now defined in includes/Cmm.h. Currently, code compiled with the -fticky-ticky flag fails to link because the macros rely on counter variables (things with names like ENT_DYN_IND_ctr being declared, but there are actually no declarations for them. I'll add those declarations to includes/RtsExternal.h so I can get something working. Really, there should be something that automatically generates both the macros that are in includes/Cmm.h and the declarations for the corresponding variables, so that they stay in sync.

Actually, maybe it would make more sense to add a new file, RtsTicky.h or something, which contains only ticky counter declarations (the same declarations that still exist in includes/StgTicky.h, which isn't used anymore), and that include that from includes/RtsExternal.h.

No -- put actual declarations for counter variables in another file, TickyCounters.h or something, and include that only from rts/Ticky.c; put extern declarations for those counters in RtsTicky.h, still included from includes/RtsExternal.h. Then later we can automatically generate both RtsTicky.h and TickyCounters.h. The reason for this is that the ticky macros are all over the place and they refer to the ticky counters, so the ticky counters have to be declared someplace that everyone includes, but of course the actual initializations only need to happen in one place. (Maybe there's a better way to do this...)

No, there don't need to be two files; I was confused. Just TickyCounters.h.