Re: [PATCH 5/5] xfs: embedd struct xfbtree into the owning structure

[Christoph Hellwig <hch@lst.de>]

On Thu, Jan 04, 2024 at 11:28:22AM -0800, Darrick J. Wong wrote:
> Though looking at buftarg allocation and my old notes from a couple of
> years ago -- a second reason for allocating the buftarg during scrub
> setup was that the list_lru_init call allocates an array that's
> O(nodes_nr) and percpu_counter_init allocates an array that's
> O(maxcpus).  At the time I decided that it was better to put those large
> contiguous memory allocations in the ->setup routine where we don't have
> any vfs/xfs locks held, can run direct reclaim, and haven't done any xfs
> work yet.

Given that we use the page LRU for the shemfs pages, I don't think we
need the buftarg LRU list at all - aging just the buffer container
doesn't make much sense.