On Fri, Jun 05, 2026 at 10:14:12AM -0600, Nico Pache wrote:

Currently the collapse_huge_page function requires the mmap_read_lock to
enter with it held, and exit with it dropped. This function moves the
unlock into its parent caller, and changes this semantic to requiring it
to enter/exit with it always unlocked.

In future patches, we need this expectation, as for in mTHP collapse, we
may have already dropped the lock, and do not want to conditionally
check for this by passing through the lock_dropped variable.

No functional change is expected as one of the first things the
collapse_huge_page function does is drop this lock before allocating the
hugepage.

Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Signed-off-by: Nico Pache <npache@redhat.com>
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Reviewed-by: Lance Yang <lance.yang@linux.dev>