[v2,00/24] Split netmem from struct page

Message

Matthew Wilcox Jan. 5, 2023, 9:46 p.m. UTC

The MM subsystem is trying to reduce struct page to a single pointer.
The first step towards that is splitting struct page by its individual
users, as has already been done with folio and slab.  This patchset does
that for netmem which is used for page pools.

There are some relatively significant reductions in kernel text size
from these changes.  They don't appear to affect performance at all,
but it's nice to save a bit of memory.

v2:
 - Rebase to next-20230105
 - Add kernel-doc for struct netmem
 - Add mlx5 compilation fixes from Jesper
 - Folded in minor nit from Alex Duyck

Matthew Wilcox (Oracle) (24):
  netmem: Create new type
  netmem: Add utility functions
  page_pool: Add netmem_set_dma_addr() and netmem_get_dma_addr()
  page_pool: Convert page_pool_release_page() to
    page_pool_release_netmem()
  page_pool: Start using netmem in allocation path.
  page_pool: Convert page_pool_return_page() to
    page_pool_return_netmem()
  page_pool: Convert __page_pool_put_page() to __page_pool_put_netmem()
  page_pool: Convert pp_alloc_cache to contain netmem
  page_pool: Convert page_pool_defrag_page() to
    page_pool_defrag_netmem()
  page_pool: Convert page_pool_put_defragged_page() to netmem
  page_pool: Convert page_pool_empty_ring() to use netmem
  page_pool: Convert page_pool_alloc_pages() to page_pool_alloc_netmem()
  page_pool: Convert page_pool_dma_sync_for_device() to take a netmem
  page_pool: Convert page_pool_recycle_in_cache() to netmem
  page_pool: Remove page_pool_defrag_page()
  page_pool: Use netmem in page_pool_drain_frag()
  page_pool: Convert page_pool_return_skb_page() to use netmem
  page_pool: Convert frag_page to frag_nmem
  xdp: Convert to netmem
  mm: Remove page pool members from struct page
  page_pool: Pass a netmem to init_callback()
  net: Add support for netmem in skb_frag
  mvneta: Convert to netmem
  mlx5: Convert to netmem

 Documentation/networking/page_pool.rst        |   5 +
 drivers/net/ethernet/marvell/mvneta.c         |  48 +--
 drivers/net/ethernet/mellanox/mlx5/core/en.h  |  10 +-
 .../net/ethernet/mellanox/mlx5/core/en/txrx.h |   4 +-
 .../net/ethernet/mellanox/mlx5/core/en/xdp.c  |  24 +-
 .../net/ethernet/mellanox/mlx5/core/en/xdp.h  |   2 +-
 .../net/ethernet/mellanox/mlx5/core/en_main.c |  12 +-
 .../net/ethernet/mellanox/mlx5/core/en_rx.c   | 130 +++++----
 include/linux/mm_types.h                      |  22 --
 include/linux/skbuff.h                        |  11 +
 include/net/page_pool.h                       | 209 +++++++++++--
 include/trace/events/page_pool.h              |  28 +-
 net/bpf/test_run.c                            |   4 +-
 net/core/page_pool.c                          | 274 +++++++++---------
 net/core/xdp.c                                |   7 +-
 15 files changed, 471 insertions(+), 319 deletions(-)

Comments

Jesse Brandeburg Jan. 6, 2023, 1:20 a.m. UTC | #1

On 1/5/2023 1:46 PM, Matthew Wilcox (Oracle) wrote:
> The MM subsystem is trying to reduce struct page to a single pointer.
> The first step towards that is splitting struct page by its individual
> users, as has already been done with folio and slab.  This patchset does
> that for netmem which is used for page pools.
> 
> There are some relatively significant reductions in kernel text size
> from these changes.  They don't appear to affect performance at all,
> but it's nice to save a bit of memory.
> 
> v2:
>   - Rebase to next-20230105
>   - Add kernel-doc for struct netmem
>   - Add mlx5 compilation fixes from Jesper
>   - Folded in minor nit from Alex Duyck

I had a brief look over the whole series and didn't see anything bad 
that stood out to me.

The series is remarkably small, with many small and easy to review 
patches, so thanks for taking the time to do those.

Reviewed-by: Jesse Brandeburg <[e-mail]>