Re: [PATCH] PM: hibernate: make compression threads configurable via kernel parameter

[Rafael J. Wysocki]

On Thu, Aug 28, 2025 at 5:30 AM luoxueqin <luoxueqin@xxxxxxxxxx> wrote:
>
>
> 在 2025/8/26 19:43, Rafael J. Wysocki 写道:
> > On Tue, Aug 26, 2025 at 11:19 AM Xueqin Luo <luoxueqin@xxxxxxxxxx> wrote:
> >> A new kernel parameter 'cmp_threads=' is introduced to
> >> allow tuning the number of compression/decompression threads at boot.
> > And why is it useful/needed?
> The number of compression/decompression threads directly impacts
> hibernate and resume time.
> In our tests(averaged over 10 runs):
>      cmp_threads   hibernate(s)   resume(s)
>              3                           12.14          18.86
>              4                           12.28          17.48
>              5                           11.09          16.77
>              6                           11.08          16.44
> With 5–6 threads, resume latency improves by ~12% compared to 3 threads.
> But on low-core systems,
> more threads may cause contention. Making it configurable allows
> integrators to balance performance
>   and CPU usage across different hardware without recompiling the kernel.

So please add this information to the changelog of the patch and resend it.

Thanks!