io_uring/rsrc: charge buffer arrays and nodes to memcg

The io_mapped_ubuf of a registered buffer has one bio_vec per page,
unless the pages coalesce into huge pages. Huge pages only count against
RLIMIT_MEMLOCK once per ring, so a buffer that maps the same 2MB folio
over and over in a way that defeats coalescing gets a full bvec array
per registration while only the one folio counts as locked. 1GB of that
registered in 100 slots took several times a 64MB memory.max, with 2.6MB
charged.

Allocate the io_mapped_ubuf and the io_rsrc_node with
GFP_KERNEL_ACCOUNT. An object reused from the ring caches stays charged
to whoever allocated it first, same as the io_kiocb cache.

Fixes: de2939388be5 ("io_uring: improve registered buffer accounting for huge pages")
Signed-off-by: Chris Mason <mason@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

0 files changed, 0 insertions, 0 deletions