fix(iwyu_tool): reduce CPU usage in job polling loop#2005
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kimgr merged 1 commit intoinclude-what-you-use:masterfrom Apr 18, 2026
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The job polling loop was sleeping 100 microseconds (10,000 wakeups/sec), causing unnecessary CPU usage when waiting for IWYU analysis jobs that take seconds to complete. 100ms (10 polls/sec) is sufficient granularity for jobs that run for seconds, with no perceptible impact on responsiveness. Addresses include-what-you-use#1995 Signed-off-by: Pierluigi Lenoci <pierluigilenoci@gmail.com>
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Hi @kimgr, @bolshakov-a — this is a small fix to reduce CPU usage in the job polling loop in |
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Looks reasonable, but I have no idea how to find the optimum value. |
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LGTM. I remember experimenting with that poll delay (it was originally zero), but I see now that we're in no rush since we're just monitoring comparatively long-running child processes. Makes sense. |
Informational: IWYU dogfood resultsinclude-what-you-use (exit: 0)fix_includes.py (exit: 0) |
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Fixes #1995
The job scheduling loop in
iwyu_tool.pyusedtime.sleep(0.0001)(100us), causing 10,000 wakeups per second while waiting for IWYU analysis jobs that typically run for seconds.This PR changes the sleep interval to
0.1seconds (10 polls/sec), which is more than sufficient granularity for long-running jobs and significantly reduces CPU and battery usage during analysis runs.