Re: [PATCH v5 0/4] mm/page_reporting: Make page reporting work on arm64 with 64KB page size

[Alexander Duyck]

On Thu, Jun 24, 2021 at 7:20 PM Gavin Shan <gshan@xxxxxxxxxx> wrote:
>
> The page reporting threshold is currently equal to @pageblock_order, which
> is 13 and 512MB on arm64 with 64KB base page size selected. The page
> reporting won't be triggered if the freeing page can't come up with a free
> area like that huge. The condition is hard to be met, especially when the
> system memory becomes fragmented.
>
> This series intends to solve the issue by having page reporting threshold
> as 5 (2MB) on arm64 with 64KB base page size. The patches are organized as:
>
>    PATCH[1/4] Fix some coding style in __page_reporting_request().
>    PATCH[2/4] Represents page reporting order with variable so that it can
>               be exported as module parameter.
>    PATCH[3/4] Allows the device driver (e.g. virtio_balloon) to specify
>               the page reporting order when the device info is registered.
>    PATCH[4/4] Specifies the page reporting order to 5, corresponding to
>               2MB in size on ARM64 when 64KB base page size is used.
>
> Changelog
> =========
> v5:
>    * Restore @page_reporting_order to @pageblock_order when
>      device is registered in PATCH[2/4] to keep "git bisect"
>      friendly at least.                                           (Alex)

These latest changes address the concerns I had.

Thanks.

- Alex