Re: [PATCH v4] KEYS: key_garbage_collector(): process in chunks

[Jarkko Sakkinen <jarkko@kernel.org>]

On Thu, Oct 29, 2026 at 04:07:05PM +0200, Jarkko Sakkinen wrote:
> keygcbench results without the patch:
> 
> unused:   min=3016.754 avg=11859.097 max=28667.645 var=141391574.712
> expired:  min=0.015 avg=12758.165 max=21516.237 var=85158284.646
> combined: min=0.015 avg=12308.631 max=28667.645 var=113477010.596
> 
> keygcbench results with the patch:
> 
> unused:   min=0.225 avg=13.991 max=853.100 var=858.700
> expired:  min=0.016 avg=30.442 max=2791.695 var=14187.539
> combined: min=0.016 avg=19.249 max=2791.695 var=5177.436

I personally would optimize all-in for variance because:

1. It is insignificant drawback for any practical keyring workload
   if the total time increases slightly.
2. Latency peaks are a signifiant drawback for any possible latency
   sensitive workload running in the system.

What I'm doing now is to find sweet spot chunk size below 1024 where
variances reaches its lowest value.

The latency part makes this change more valuable than focusing on
only on the regression itself.

Br, Jarkko