On 7/21/2026 9:28 AM, [email protected] wrote:
From: Kyrylo Tkachov <[email protected]>
The stage 2 and stage 3 object comparison runs one command per object in a
serial shell loop. Everything after it waits while an otherwise idle machine
compares thousands of objects.
Generate one make target per object and run the comparisons through $(MAKE),
so they share the original jobserver. Keep the generated makefile and result
shards invocation-specific, clean them on normal and signal exits, and sort
the shards before creating the traditional .bad_compare diagnostic. Files in
the exclusion list still only warn. Comparator statuses other than zero or
one now report an operational error instead of being treated as equal.
The tail-based fallback for cmp implementations without byte skipping used
fixed temporary names. Give those files process-specific names, clean them
with a trap, and preserve the same status contract for tail failures and
signals.
On highly parallel AArch64 and x86_64 systems this reduces comparison wall
time by about 95%.
ChangeLog:
* Makefile.tpl ([+compare-target+]): Run object comparisons through an
invocation-specific parallel sub-make. Collect sorted failure shards
and clean temporary state on exit.
* Makefile.in: Regenerate.
* configure: Regenerate.
config/ChangeLog:
* acx.m4 (ACX_PROG_CMP_IGNORE_INITIAL): Use process-specific temporary
files and clean them on exit. Diagnose tail failures as errors.
Signed-off-by: Kyrylo Tkachov <[email protected]>
Given the utility of the bootstrap comparison test, I hope you you
tested with a forced failure to ensure it'll trigger failures properly.
Assuming you've done a force failure test, OK.
jeff
