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@xxxxxxxxxx> # iterative Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> Suggested-by: Jakub Kicinski <kuba@xxxxxxxxxx> # while (count) Signed-off-by: Alexander Lobakin <aleksander.lobakin@xxxxxxxxx> --- include/net/page_pool/types.h | 6 +- include/net/xdp.h | 16 +++-- net/core/page_pool.c | 109 ++++++++++++++++++++++------------ net/core/xdp.c | 29 +-------- 4 files changed, 87 insertions(+), 73 deletions(-) diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h index 1ea16b0e9c79..05a864031271 100644 --- a/include/net/page_pool/types.h +++ b/include/net/page_pool/types.h @@ -259,8 +259,7 @@ void page_pool_disable_direct_recycling(struct page_pool *pool); void page_pool_destroy(struct page_pool *pool); void page_pool_use_xdp_mem(struct page_pool *pool, void (*disconnect)(void *), const struct xdp_mem_info *mem); -void page_pool_put_netmem_bulk(struct page_pool *pool, netmem_ref *data, - u32 count); +void page_pool_put_netmem_bulk(netmem_ref *data, u32 count); #else static inline void page_pool_destroy(struct page_pool *pool) { @@ -272,8 +271,7 @@ static inline void page_pool_use_xdp_mem(struct page_pool *pool, { } -static inline void page_pool_put_netmem_bulk(struct page_pool *pool, - netmem_ref *data, u32 count) +static inline void page_pool_put_netmem_bulk(netmem_ref *data, u32 count) { } #endif diff --git a/include/net/xdp.h b/include/net/xdp.h index f4020b29122f..9e7eb8223513 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -11,6 +11,8 @@ #include <linux/netdevice.h> #include <linux/skbuff.h> /* skb_shared_info */ +#include <net/page_pool/types.h> + /** * DOC: XDP RX-queue information * @@ -193,14 +195,12 @@ xdp_frame_is_frag_pfmemalloc(const struct xdp_frame *frame) #define XDP_BULK_QUEUE_SIZE 16 struct xdp_frame_bulk { int count; - void *xa; netmem_ref q[XDP_BULK_QUEUE_SIZE]; }; static __always_inline void xdp_frame_bulk_init(struct xdp_frame_bulk *bq) { - /* bq->count will be zero'ed when bq->xa gets updated */ - bq->xa = NULL; + bq->count = 0; } static inline struct skb_shared_info * @@ -317,10 +317,18 @@ void __xdp_return(void *data, struct xdp_mem_info *mem, bool napi_direct, void xdp_return_frame(struct xdp_frame *xdpf); void xdp_return_frame_rx_napi(struct xdp_frame *xdpf); void xdp_return_buff(struct xdp_buff *xdp); -void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq); void xdp_return_frame_bulk(struct xdp_frame *xdpf, struct xdp_frame_bulk *bq); +static inline void xdp_flush_frame_bulk(struct xdp_frame_bulk *bq) +{ + if (unlikely(!bq->count)) + return; + + page_pool_put_netmem_bulk(bq->q, bq->count); + bq->count = 0; +} + static __always_inline unsigned int xdp_get_frame_len(const struct xdp_frame *xdpf) { diff --git a/net/core/page_pool.c b/net/core/page_pool.c index 4c85b77cfdac..10cef95f12e3 100644 --- a/net/core/page_pool.c +++ b/net/core/page_pool.c @@ -839,9 +839,41 @@ void page_pool_put_unrefed_page(struct page_pool *pool, struct page *page, } EXPORT_SYMBOL(page_pool_put_unrefed_page); +static void page_pool_recycle_ring_bulk(struct page_pool *pool, + netmem_ref *bulk, + u32 bulk_len) +{ + bool in_softirq; + u32 i; + + /* Bulk produce into ptr_ring page_pool cache */ + in_softirq = page_pool_producer_lock(pool); + + for (i = 0; i < bulk_len; i++) { + if (__ptr_ring_produce(&pool->ring, (__force void *)bulk[i])) { + /* ring full */ + recycle_stat_inc(pool, ring_full); + break; + } + } + + page_pool_producer_unlock(pool, in_softirq); + recycle_stat_add(pool, ring, i); + + /* Hopefully all pages were returned into ptr_ring */ + if (likely(i == bulk_len)) + return; + + /* + * ptr_ring cache is full, free remaining pages outside producer lock + * since put_page() with refcnt == 1 can be an expensive operation. + */ + for (; i < bulk_len; i++) + page_pool_return_page(pool, bulk[i]); +} + /** * page_pool_put_netmem_bulk() - release references on multiple netmems - * @pool: pool from which pages were allocated * @data: array holding netmem references * @count: number of entries in @data * @@ -854,52 +886,55 @@ EXPORT_SYMBOL(page_pool_put_unrefed_page); * Please note the caller must not use data area after running * page_pool_put_netmem_bulk(), as this function overwrites it. */ -void page_pool_put_netmem_bulk(struct page_pool *pool, netmem_ref *data, - u32 count) +void page_pool_put_netmem_bulk(netmem_ref *data, u32 count) { - int i, bulk_len = 0; - bool allow_direct; - bool in_softirq; - - allow_direct = page_pool_napi_local(pool); + u32 bulk_len = 0; - for (i = 0; i < count; i++) { + for (u32 i = 0; i < count; i++) { netmem_ref netmem = netmem_compound_head(data[i]); - /* It is not the last user for the page frag case */ - if (!page_pool_is_last_ref(netmem)) - continue; - - netmem = __page_pool_put_page(pool, netmem, -1, allow_direct); - /* Approved for bulk recycling in ptr_ring cache */ - if (netmem) + if (page_pool_is_last_ref(netmem)) data[bulk_len++] = netmem; } - if (!bulk_len) - return; - - /* Bulk producer into ptr_ring page_pool cache */ - in_softirq = page_pool_producer_lock(pool); - for (i = 0; i < bulk_len; i++) { - if (__ptr_ring_produce(&pool->ring, (__force void *)data[i])) { - /* ring full */ - recycle_stat_inc(pool, ring_full); - break; + count = bulk_len; + while (count) { + netmem_ref bulk[XDP_BULK_QUEUE_SIZE]; + struct page_pool *pool = NULL; + bool allow_direct; + u32 foreign = 0; + + bulk_len = 0; + + for (u32 i = 0; i < count; i++) { + struct page_pool *netmem_pp; + netmem_ref netmem = data[i]; + + netmem_pp = netmem_get_pp(netmem); + if (unlikely(!pool)) { + pool = netmem_pp; + allow_direct = page_pool_napi_local(pool); + } else if (netmem_pp != pool) { + /* + * If the netmem belongs to a different + * page_pool, save it for another round. + */ + data[foreign++] = netmem; + continue; + } + + netmem = __page_pool_put_page(pool, netmem, -1, + allow_direct); + /* Approved for bulk recycling in ptr_ring cache */ + if (netmem) + bulk[bulk_len++] = netmem; } - } - recycle_stat_add(pool, ring, i); - page_pool_producer_unlock(pool, in_softirq); - /* Hopefully all pages was return into ptr_ring */ - if (likely(i == bulk_len)) - return; + if (bulk_len) + page_pool_recycle_ring_bulk(pool, bulk, bulk_len); - /* ptr_ring cache full, free remaining pages outside producer lock - * since put_page() with refcnt == 1 can be an expensive operation - */ - for (; i < bulk_len; i++) - page_pool_return_page(pool, data[i]); + count = foreign; + } } EXPORT_SYMBOL(page_pool_put_netmem_bulk); 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; -- 2.47.1