[oech3]

Allow running bad-speed.sh against static stty.
This is needed for rustix migration too.

[codspeed]

Merging this PR will regress 1 benchmark

2 warnings, 1 note

⚠️ 122 benchmarks are dominated by system calls

System calls cannot be simulated consistently and are left out of the measure. The reported value understates the real cost. Switch to the Walltime instrument to measure them.

Learn more about system calls

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⚠️ 1 benchmark with a significant change ran on different hardware

Its base and head results were measured on machines with a different CPU, core count or memory, so the change might not come from the code. Run base and head on the same runner type.

Learn more about Macro Runners

See affected benchmarks

ℹ️ 1 benchmark has no flamegraph

The flamegraph wasn't generated: most of the time was spent in runtime internals, which would leave nothing useful to analyze.

See affected benchmarks

⚡ 1 improved benchmark
❌ 1 regressed benchmark
✅ 399 untouched benchmarks
⏩ 70 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	CPU Simulation	du_wide_tree[(5000, 500)]	15.1 ms	15.7 ms	-3.87%
⚡	Memory	du_deep_tree[(100, 3)]	82.4 KB	76.5 KB	+7.68%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing oech3:stty-gnu-mock (d7aa975) with main (43eb620)}

Footnotes

1. 70 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[xtqqczze]

Why do we return ENOSPC ("No space left on device") when LD_PRELOAD environment variable is set and contains k.so?

[oech3]

Because GnuTests checks them. But we can choice any errno since the message is not checked by GNU.

[sylvestre]

sorry but i don't want test-specific code in stty that fakes the result of bad-speed.sh
if the test can't work with a static binary, let's skip it with a patch in util/gnu-patches instead

[oech3]

No. Patch is impossible in this case.

[oech3]

I did this since you did not hope to skip the test at #15299 .
It is possible to supress vervosity in the main code by separating fn and put it under test code (I updated #15299 to do that).