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feat(metrics): report VMM thread CPU usage - #6264
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ilstam
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| /// Metric for signaling a panic has occurred. | ||
| pub panic_count: SharedStoreMetric, | ||
| /// CPU time the VMM thread used since the last metrics flush, in microseconds. | ||
| pub thread_cpu_us: SharedIncMetric, |
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Can we name it "main_thread_cpu_us" for clarity? Similar for the other variables and function names (last_main_thread_cpu_us, update_main_thread_cpu_usage).
| /// The metrics are flushed from the event loop, so the calling thread is the VMM thread. | ||
| fn update_thread_cpu_usage(&mut self) { | ||
| let thread_cpu_us = get_time_us(ClockType::ThreadCpu); | ||
| METRICS |
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Instead of adding to it every time, can't we just set it to get_time_us(ClockType::ThreadCpu) directly?
The main thread runs the event loop and emulates every device that has no worker thread of its own, but no metric shows how busy it is, so a saturated main thread can only be spotted with host tools. Add vmm.main_thread_cpu_us, the CPU time the main thread has used, read from CLOCK_THREAD_CPUTIME_ID each time the metrics are written. The seccomp filters already allow clock_gettime. Signed-off-by: Richard Durkee <56232628+Richard-Durkee@users.noreply.github.com>
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vmm.thread_cpu_us: the CPU time the VMM thread used since the last metrics flush. It is read withclock_gettime(CLOCK_THREAD_CPUTIME_ID)when the metrics are written.Reason
All device emulation runs on the VMM thread, but no metric shows how busy that thread is.
thread_cpu_us / flush intervalgives its utilization, so a saturated VMM thread can be spotted without host tools liketop -H.License Acceptance
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license. For more information on following Developer Certificate of Origin and signing off your commits, please check
CONTRIBUTING.md.PR Checklist
tools/devtool checkbuild --allto verify that the PR passesbuild checks on all supported architectures.
tools/devtool checkstyle --no-clippyto verify that the PRpasses the automated style checks.
how they are solving the problem in a clear and encompassing way.
in the PR.
CHANGELOG.md.Runbook for Firecracker API changes.
integration tests.
TODO.rust-vmm.