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

[Gavin Shan]

On 6/26/21 12:18 AM, Alexander Duyck wrote:
> 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 again for your review, Alex. However, v4 was merged and it's fine
since v5 only resolves 'git-bisect' friendly issue on PATCH[v4 2/4].

Thanks,
Gavin