pprof: Tolerate stack frame timestamps arriving out of order #371
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From the bug report, it seems as though this rarely happens, so this is a nice simple workaround that probably won't meaningfully impact the results. 👍 The only improvement I can think of is actually swapping the samples (added complexity and overhead for dubious value 👎). |
saunderst
approved these changes
Nov 10, 2022
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Thanks! |
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Resolves #367. When sampling multiple processes, the order in which the samples arrive at the stats recorder is nondeterministic. That can result in awkward calculations where the previous sample seems to have arrived after the current one.
There are several options for handling this. We could drop the current sample, or calculate the elapsed time backwards (treat the previous time as the next one), or assume that the timestamps arrived at the same time, etc. This workaround uses the latter. That is, we assume that no time has elapsed between the "previous" sample and the one that we're currently processing.
@saunderst, WDYT?