Re: [PATCH v4] mm/page_reporting: Add page_reporting_delay_ms module parameter

SJ Park <[email protected]> Fri, 31 Jul 2026 17:02:53 -0700
Newsgroups org.kernel.vger.linux-doc,org.kernel.vger.linux-kernel,org.kvack.linux-mm
Message-ID <[email protected]>
Brendan changed his mail address [1].  I added him to the recipient list.

On Fri, 31 Jul 2026 19:37:05 +0000 [email protected] wrote:

> From: Pratyush Mallick <[email protected]>
> 
> Free page reporting currently hardcodes a 2-second interval between
> reports. This rigid delay cannot accommodate diverse guest workloads.
> 
> This patch introduces a module parameter, page_reporting_delay_ms
> (default: 2000), allowing users to tune the reporting rate:
>  - Lower values enable aggressive memory reclamation by returning unused
>    pages to the host immediately.
>  - Higher values help batch pages during spiky allocation/free churn,
>    reducing hypercalls and nested page fault overheads.
> 
> Setting the delay to 0 is safe and execution is strictly gated by:
>  - reporting is only triggered by high-order page frees.
>  - expensive hypercalls are bounded by a slot capacity watermark check
>    before proceeding.

Looks good and making sense to me.

> 
> Signed-off-by: Pratyush Mallick <[email protected]>

Reviewed-by: SJ Park <[email protected]>

[1] https://lore.kernel.org/[email protected]


Thanks,
SJ

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