Fix high CPU usage when game paused#32
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jserv
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Jul 16, 2026
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Check https://cbea.ms/git-commit/ carefully and enforce.
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Provide test case for clarification/validation. |
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Before this patch After this patch |
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Initialize read_attr to false instead of relying on Ctrl-P to reproduce the issue deterministically. Without the patch, select() continues monitoring the readable device file descriptor and returns immediately, causing a busy loop and a significant increase in CPU usage. With the patch applied, the device file descriptor is excluded and select() blocks on standard input, keeping CPU usage negligible. |
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When board display is paused, read_attr prevents task_io from consuming data from /dev/kxo. The descriptor can remain readable, so keeping it in the select set makes select return immediately and repeatedly run the main loop. Exclude /dev/kxo from the descriptor set and wait only for stdin while paused. This lets select sleep until keyboard input resumes or exits the program, avoiding needless CPU use. Change-Id: I5c44adeed192167998cc71ca3174bc0edc50cdc4
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Thank @tobiichi3227 for contributing! |
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Stop reading
kxodevice when game is paused.Only read STDIN for resume game.
Change-Id: I5c44adeed192167998cc71ca3174bc0edc50cdc4
Summary by cubic
Fix high CPU use when paused by excluding
/dev/kxofromselectand waiting only onSTDIN.Written for commit 0000878. Summary will update on new commits.