On Sun, Dec 14, 2025 at 10:20:12AM -0600, Segher Boessenkool wrote:
> Hi!
>
> On Sun, Dec 14, 2025 at 06:32:44PM +0530, Mukesh Kumar Chaurasiya wrote:
> >
> > | Test | With Patch | Without Patch | % Change |
> > | --------------- | ---------- | ------------- | -------- |
> > | fork usec/op | 833.986 | 814.809 | +2.35% |
>
> What causes this regression, did you investigate? Maybe there is
> something simple you can do to avoid this degradation :-) All other
> numbers look just fine :-)
>
Hey,
I ran this multiple times and took the average this time, below are the
results:
===========================================
Without patch
===========================================
╰─❯ perf bench syscall fork
# Running 'syscall/fork' benchmark:
# Executed 10,000 fork() calls
Total time: 8.514 [sec]
851.415300 usecs/op
1,174 ops/sec
╰─❯ perf bench syscall fork
# Running 'syscall/fork' benchmark:
# Executed 10,000 fork() calls
Total time: 8.572 [sec]
857.293600 usecs/op
1,166 ops/sec
╰─❯ perf bench syscall fork
# Running 'syscall/fork' benchmark:
# Executed 10,000 fork() calls
Total time: 8.695 [sec]
869.536500 usecs/op
1,150 ops/sec
===========================================
With patch
===========================================
╰─❯ perf bench syscall fork
# Running 'syscall/fork' benchmark:
# Executed 10,000 fork() calls
Total time: 8.482 [sec]
848.241300 usecs/op
1,178 ops/sec
╰─❯ perf bench syscall fork
# Running 'syscall/fork' benchmark:
# Executed 10,000 fork() calls
Total time: 8.623 [sec]
862.389000 usecs/op
1,159 ops/sec
╰─❯ perf bench syscall fork
# Running 'syscall/fork' benchmark:
# Executed 10,000 fork() calls
Total time: 8.530 [sec]
853.037200 usecs/op
1,172 ops/sec
===========================================
Average:
===========================================
With Patch:
854.4964 usecs/op
1169 ops/sec
Without patch:
859.4151 usecs/op
1163 ops/sec
That's ~0.5% improvement when i take average through the runs.
This we can ignore as a standard deviation and consider that there are
no regression for these.
Regards,
Mukesh
> > | Test | With Patch | Without Patch | % Change |
> > | --------------- | ---------- | ------------- | -------- |
> > | fork ops/sec | 1,199 | 1,227 | -2.28% |
>
> (Same thing seen from another side)
>
>
> Segher
