On 2025/8/4 23:40, Usama Arif wrote:

From: David Hildenbrand <redacted>

Let's allow for making MADV_COLLAPSE succeed on areas that neither have
VM_HUGEPAGE nor VM_NOHUGEPAGE when we have THP disabled
unless explicitly advised (PR_THP_DISABLE_EXCEPT_ADVISED).

MADV_COLLAPSE is a clear advice that we want to collapse.

Note that we still respect the VM_NOHUGEPAGE flag, just like
MADV_COLLAPSE always does. So consequently, MADV_COLLAPSE is now only
refused on VM_NOHUGEPAGE with PR_THP_DISABLE_EXCEPT_ADVISED,
including for shmem.

Co-developed-by: Usama Arif <redacted>
Signed-off-by: Usama Arif <redacted>
Signed-off-by: David Hildenbrand <redacted>
---

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