Add internals for stackdiff tool #3286
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Motivation: Our alloc regression workflows are somewhat disparate: on macOS we have dtrace and a script to diff two ouputs. On Linux we have heaptrack and bpftrace but no way to analyze their outputs. Diffing output from these tools can be quite tedious if the stacks vary even a little (because the compiler decided to not inline a function, for example). Most of the tedium in this workflow is from pairing up equivalent stacks across the two inputs. We can make this easier to do by ranking suggestions based on how similar they are and letting the user decide whether to accept the match or not. Modifications: - Add a subpackage with some internals for parsing heaptrack, aggregating stacks, and measuring the similarity between them - The CLI took is currently a no-op, it'll be added in subsequent PRs Result: Easier to diagnose alloc regressions
Lukasa
approved these changes
Jul 7, 2025
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Motivation:
Our alloc regression workflows are somewhat disparate: on macOS we have dtrace and a script to diff two ouputs. On Linux we have heaptrack and bpftrace but no way to analyze their outputs.
Diffing output from these tools can be quite tedious if the stacks vary even a little (because the compiler decided to not inline a function, for example).
Most of the tedium in this workflow is from pairing up equivalent stacks across the two inputs. We can make this easier to do by ranking suggestions based on how similar they are and letting the user decide whether to accept the match or not.
Modifications:
Result:
Easier to diagnose alloc regressions