Re: [PATCH 1/4] mm/compaction: stop recording free page order in page->private

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 6/29/26 10:56 AM, Zi Yan wrote:
> Commit 733aea0b3a7bb ("mm/compaction: add support for >0 order folio
> memory compaction.") stores isolated free pages in an array indexed by free
> page orders, it is no longer needed to store the order in each page's
> ->private field. And there is no code using the stored order. Stop doing
> that.
> 
> It also prepares for an upcoming change that ensures subpage->private is

I noticed that people tend to avoid using the term "subpage" now, though 
I understand what you mean by it here. :)

[1] https://lore.kernel.org/all/20260623125723.2503832-1-dev.jain@arm.com/

> zero at page free time and the removal of set_page_private(0) from
> prep_compound_tail(). In alloc_contig_frozen_range_noprof(),
> isolate_freepages_range() is used to grab free pages from buddy allocator
> and it leaves the aforementioned page->private set until
> either split_free_frozen_pages() or prep_new_page() is called. That
> triggers the upcoming subpage->private nonzero check along once
> set_page_private(0) is removed from prep_compound_tail(), which is called
> via prep_new_page().
> 
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---

LGTM.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>