Improve CPU usage efficiency #1448
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src/windows/process.rs
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| let global_kernel_time = filetime_to_u64(fglobal_kernel_time); | ||
| let global_user_time = filetime_to_u64(fglobal_user_time); | ||
| // by default, use previous values | ||
| let mut global_kernel_time: u64 = p.cpu_calc_values.old_system_sys_cpu; |
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At this point, why not just return the previously computed cpu usage?
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I apologize for my significant oversight. I revised the code to return the unchanged process CPU usage if the last_update field hasn't exceeded the time it takes to update the CPU values. It should be good now. Again, passed all cargo fmt, clippy and test commands.
…rather than re-calculating using old values.
src/windows/process.rs
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| // FIXME: should these values be stored in one place to make use of | ||
| // `MINIMUM_CPU_UPDATE_INTERVAL`? | ||
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| if p.cpu_calc_values.last_update.elapsed() <= MINIMUM_CPU_UPDATE_INTERVAL { |
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This can be put at the very beginning of this function, no need for all the variable initializations and the GetProcessTimes call.
GuillaumeGomez
approved these changes
Jan 10, 2025
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Thanks! |
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Problem
The
compute_cpu_usagefunction relied on redundant operations and inefficient handling of cached system times. This could lead to unnecessary updates to system times, resulting in reduced efficiency and increased overhead.Solution
I updated the function to use cached values unless the time elapsed since the previous values were cached exceeds MINIMUM_CPU_UPDATE_INTERVAL, ensuring system times are only refreshed when necessary.
GetSystemTimes, andfiletime_to_u64.Now, after each call to
compute_cpu_usageif the last time these values were retrieved ( a call toGetSystemTimestook place ) is less than MINIMUM_CPU_UPDATE_INTERVAL ( system values haven't updated ) the function will use the values used previously. Otherwise,GetSystemTimeswill be called, values will be retrieved, and an Instant::now() value will be saved in cpu_calc_values to determine the timeGetSystemTimeswas last called.Tests
cargo test.Other
cargo fmtandcargo clippywere ran successfully.