> On 4 Aug 2026, at 18:51, Jeffrey Law <[email protected]> wrote:
>
>
>
> 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.
>
Yes, I did corrupt stage2 tree.o and the comparison failed and the failing file
was listed.
Thanks again for the reviews
Kyrill
> jeff
