Re: [PATCH] mm/rmap: synchronize lock and unlock target in anon_vma_clone

From: Seohyun Kim

Date: Sun Aug 16 2026 - 07:51:29 EST


On 8/15/26 14:21, Barry Song wrote:

On Fri, Aug 14, 2026 at 2:33 PM Eric Kim <seohyun.kim@xxxxxxxxxx> wrote:
Currently, in anon_vma_clone(), src vma's anon_vma is assigned to
active_anon_vma and is used when unlocking anon_vma after linking new
AVCs. However, the anon_vma is locked using src->anon_vma, instead of
active_anon_vma, making the lock and unlock target inconsistent.
I'm not a native speaker, but I feel the lock and unlock are actually
consistent and operate on the same anon_vma. The code just looks
unpaired: one uses src->anon_vma, while the other uses
active_anon_vma. But aren't they actually the same thing?
You're right. My original commit message does come as confusing
because it sounds like there's an actual lock/unlock target mismatch.
(I'm not a native speaker too) My intent was to match the variable
name for locking and unlocking, and since active_anon_vma is the
implemented alias for src->anon_vma, anon_vma_clone() should
consistently use active_anon_vma. Should I send a v2 to clarify the commit
message?
Not an objection to the patch; I just find the changelog a bit
confusing.

Use active_anon_vma for both locking and unlocking.

Signed-off-by: Eric Kim <seohyun.kim@xxxxxxxxxx>
Best Regards
Barry

Thanks for the feedback.

Eric Kim