[PATCH net-next v1 00/11] xdp: page_pool fixes and in-flight accounting

Jesper Dangaard Brouer
2019-06-13T18:28:13Z

This patchset fix page_pool API and users, such that drivers can use it for
DMA-mapping. A number of places exist, where the DMA-mapping would not get
released/unmapped, all these are fixed. This occurs e.g. when an xdp_frame
gets converted to an SKB. As network stack doesn't have any callback for XDP
memory models.

The patchset also address a shutdown race-condition. Today removing a XDP
memory model, based on page_pool, is only delayed one RCU grace period. This
isn't enough as redirected xdp_frames can still be in-flight on different
queues (remote driver TX, cpumap or veth).

We stress that when drivers use page_pool for DMA-mapping, then they MUST
use one packet per page. This might change in the future, but more work lies
ahead, before we can lift this restriction.

This patchset change the page_pool API to be more strict, as in-flight page
accounting is added.

---

Ilias Apalodimas (2):
net: page_pool: add helper function to retrieve dma addresses
net: page_pool: add helper function to unmap dma addresses

Jesper Dangaard Brouer (9):
xdp: fix leak of IDA cyclic id if rhashtable_insert_slow fails
xdp: page_pool related fix to cpumap
veth: use xdp_release_frame for XDP_PASS
page_pool: introduce page_pool_free and use in mlx5
mlx5: more strict use of page_pool API
xdp: tracking page_pool resources and safe removal
xdp: force mem allocator removal and periodic warning
xdp: add tracepoints for XDP mem
page_pool: add tracepoints for page_pool with details need by XDP

drivers/net/ethernet/mellanox/mlx5/core/en_main.c | 12 +-
drivers/net/ethernet/mellanox/mlx5/core/en_rx.c | 3 -
drivers/net/veth.c | 1
include/net/page_pool.h | 69 +++++++++++-
include/net/xdp.h | 15 +++
include/net/xdp_priv.h | 23 ++++
include/trace/events/page_pool.h | 87 +++++++++++++++
include/trace/events/xdp.h | 115 ++++++++++++++++++++
kernel/bpf/cpumap.c | 3 +
net/core/net-traces.c | 4 +
net/core/page_pool.c | 87 +++++++++++++--
net/core/xdp.c | 120 ++++++++++++++++++---
12 files changed, 494 insertions(+), 45 deletions(-)
create mode 100644 include/net/xdp_priv.h
create mode 100644 include/trace/events/page_pool.h

--