Cataclysm-dda: 10x+ slowdown due to process_fields (85%) and spread_gas (45%)

[FunnyMan3595]

Describe the bug

My savegame has become exceedingly slow recently, with a 5-minute reading step taking about 3 real seconds. This is a 10x+ slowdown, as a fresh save with the same options and character template-copied over will get over an hour of reading progress in the same real time.

Steps To Reproduce

1. Load attached save.
2. Begin reading.
3. Observe lag.

Expected behavior

The game may slow down as the save gets more complex, but hopefully not this far without exceptional circumstances.

Screenshots

There's very little nearby, just my car (with a bunch of loot) and the entrance to a cold lab (which is partially raided, but fairly unexceptional):
image

Versions and configuration

• OS: Windows
  
  
  
  • OS Version: MINGW/CYGWIN/MSYS2 on Windows 8.1
  
  
• Game Version: 0.E-2 [64-bit]
• Graphics Version: Tiles
• Game Language: System language [English]
• Mods loaded: [
  Dark Days Ahead [dda],
  Disable NPC Needs [no_npc_food],
  Magiclysm [magiclysm],
  No Monsters [Only_Wildlife],
  Stats Through Skills [StatsThroughSkills]
  ]

Additional context

Save: Laggy_East_Walthill.zip

[FunnyMan3595]

After further experimentation, heading ~15 map tiles south down the road does restore my reading speed to approximately normal, which strongly suggests that it's the cold lab to blame for the lag.

[stale[bot]]

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[stale[bot]]

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