Re: [RFC 1/1] rwsem: Shrink rwsem by one pointer

[Waiman Long <llong@redhat.com>]

On 2/17/26 2:08 PM, Matthew Wilcox (Oracle) wrote:
> Instead of embedding a list_head in struct rw_semaphore, store a pointer
> to the first waiter.  The list of waiters remains a doubly linked list
> so we can efficiently add to the tail of the list, remove from the front
> (or middle) of the list.
>
> Some of the list manipulation becomes more complicated, but it's a
> reasonable tradeoff on the slow paths to shrink some core data structures
> like struct inode.

If the goal is to use only one pointer for the rwsem structure, would it 
make sense to change list_head to hlist_head for instance? At least we 
have existing helpers that can be used instead of making our own coding 
convention here.

Cheers,
Longman