[GH-ISSUE #434] `PROTON_LOG=1` causing game <1fps in Space Rock Breaker #272

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opened 2026-10-15 12:59:05 +00:00 by bsakaguchi · 1 comment

bsakaguchi commented

2026-10-15 12:59:05 +00:00

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Originally created by @altano on GitHub (Jun 15, 2026).
Original GitHub issue: https://github.com/games-on-whales/wolf/issues/434

The default Steam app sets PROTON_LOG=1 (config.include.toml#L138). Some games, e.g. Space Rock Breaker, write several MB/s, which makes almost all the UI stutter at <1 fps while GPU and CPU sit idle. This game is probably doing something wrong to be writing so much to the log, but regardless, PROTON_LOG=1 gives me <1fps and removing the logging gives me 60fps.

strace -c of the render thread during a freeze showed 98% of its time in write() to ~/steam-<appid>.log (~2.5 MB/s of trace:unwind). Setting WINEDEBUG=-all (or dropping PROTON_LOG=1) fully fixes it.

Suggested fix: don't enable PROTON_LOG=1 by default. Make it opt-in for debugging instead.

Originally created by @altano on GitHub (Jun 15, 2026). Original GitHub issue: https://github.com/games-on-whales/wolf/issues/434 The default Steam app sets `PROTON_LOG=1` ([config.include.toml#L138](https://github.com/games-on-whales/wolf/blob/980a2919bed72037f390a6be40ffeef18d932a5c/src/moonlight-server/state/default/config.include.toml#L138)). Some games, e.g. Space Rock Breaker, write several MB/s, which makes almost all the UI stutter at <1 fps while GPU and CPU sit idle. This game is probably doing something wrong to be writing so much to the log, but regardless, `PROTON_LOG=1` gives me <1fps and removing the logging gives me 60fps. `strace -c` of the render thread during a freeze showed 98% of its time in `write()` to `~/steam-<appid>.log` (~2.5 MB/s of `trace:unwind`). Setting `WINEDEBUG=-all` (or dropping `PROTON_LOG=1`) fully fixes it. Suggested fix: don't enable `PROTON_LOG=1` by default. Make it opt-in for debugging instead.

bsakaguchi commented

2026-10-15 12:59:06 +00:00

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@ABeltramo commented on GitHub (Jun 17, 2026):

That makes sense, honestly PROTON_LOG=1 is a relic from a long time ago when we were first building the images, it should've been removed long ago.

I'll mention this in a PR that is currently changing the config.toml, thanks for reporting.

@ABeltramo commented on GitHub (Jun 17, 2026): That makes sense, honestly `PROTON_LOG=1` is a relic from a long time ago when we were first building the images, it should've been removed long ago. I'll mention this in a PR that is currently changing the `config.toml`, thanks for reporting.