page_pool: allow mixing PPs within one bulk

The main reason for this change was to allow mixing pages from different
&page_pools within one &xdp_buff/&xdp_frame. Why not? With stuff like
devmem and io_uring zerocopy Rx, it's required to have separate PPs for
header buffers and payload buffers.
Adjust xdp_return_frame_bulk() and page_pool_put_netmem_bulk(), so that
they won't be tied to a particular pool. Let the latter create a
separate bulk of pages which's PP is different from the first netmem of
the bulk and process it after the main loop.
This greatly optimizes xdp_return_frame_bulk(): no more hashtable
lookups and forced flushes on PP mismatch. Also make
xdp_flush_frame_bulk() inline, as it's just one if + function call + one
u32 read, not worth extending the call ladder.

Co-developed-by: Toke Høiland-Jørgensen <toke@redhat.com> # iterative
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org> # while (count)
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://patch.msgid.link/20241211172649.761483-2-aleksander.lobakin@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 1 insertions, 28 deletions

diff --git a/net/core/xdp.c b/net/core/xdp.c
index 938ad15c9857..56127e8ec85f 100644
--- a/net/core/xdp.c
+++ b/net/core/xdp.c
@@ -511,46 +511,19 @@ EXPORT_SYMBOL_GPL(xdp_return_frame_rx_napi);
  * xdp_frame_bulk is usually stored/allocated on the function
  * call-stack to avoid locking penalties.
  */
-void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq)
-{
-	struct xdp_mem_allocator *xa = bq->xa;
-
-	if (unlikely(!xa || !bq->count))
-		return;
-
-	page_pool_put_netmem_bulk(xa->page_pool, bq->q, bq->count);
-	/* bq->xa is not cleared to save lookup, if mem.id same in next bulk */
-	bq->count = 0;
-}
-EXPORT_SYMBOL_GPL(xdp_flush_frame_bulk);
 
 /* Must be called with rcu_read_lock held */
 void xdp_return_frame_bulk(struct xdp_frame *xdpf,
 			   struct xdp_frame_bulk *bq)
 {
-	struct xdp_mem_info *mem = &xdpf->mem;
-	struct xdp_mem_allocator *xa;
-
-	if (mem->type != MEM_TYPE_PAGE_POOL) {
+	if (xdpf->mem.type != MEM_TYPE_PAGE_POOL) {
 		xdp_return_frame(xdpf);
 		return;
 	}
 
-	xa = bq->xa;
-	if (unlikely(!xa)) {
-		xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
-		bq->count = 0;
-		bq->xa = xa;
-	}
-
 	if (bq->count == XDP_BULK_QUEUE_SIZE)
 		xdp_flush_frame_bulk(bq);
 
-	if (unlikely(mem->id != xa->mem.id)) {
-		xdp_flush_frame_bulk(bq);
-		bq->xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
-	}
-
 	if (unlikely(xdp_frame_has_frags(xdpf))) {
 		struct skb_shared_info *sinfo;
 		int i;