On 2025/10/23 02:37, Nico Pache wrote:

Pass an order and offset to collapse_huge_page to support collapsing anon
memory to arbitrary orders within a PMD. order indicates what mTHP size we
are attempting to collapse to, and offset indicates were in the PMD to
start the collapse attempt.

For non-PMD collapse we must leave the anon VMA write locked until after
we collapse the mTHP-- in the PMD case all the pages are isolated, but in
the mTHP case this is not true, and we must keep the lock to prevent
changes to the VMA from occurring.

Signed-off-by: Nico Pache <npache@redhat.com>
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LGTM. And passed my mTHP collapse testing cases. So:
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>