From: Jason Xing This patch is to prepare for later batch xmit in generic path. Add a new socket option to provide an alternative to achieve a higher overall throughput. skb_batch will be used to store newly allocated skb at one time in the xmit path. Signed-off-by: Jason Xing --- Documentation/networking/af_xdp.rst | 9 ++++++++ include/net/xdp_sock.h | 2 ++ include/uapi/linux/if_xdp.h | 1 + net/xdp/xsk.c | 32 +++++++++++++++++++++++++++++ tools/include/uapi/linux/if_xdp.h | 1 + 5 files changed, 45 insertions(+) diff --git a/Documentation/networking/af_xdp.rst b/Documentation/networking/af_xdp.rst index 50d92084a49c..1194bdfaf61e 100644 --- a/Documentation/networking/af_xdp.rst +++ b/Documentation/networking/af_xdp.rst @@ -447,6 +447,15 @@ mode to allow application to tune the per-socket maximum iteration for better throughput and less frequency of send syscall. Allowed range is [32, xs->tx->nentries]. +XDP_GENERIC_XMIT_BATCH +---------------------- + +It provides an option that allows application to use batch xmit in the copy +mode. Batch process minimizes the number of grabbing/releasing queue lock +without redundant actions compared to before to gain the overall performance +improvement whereas it might increase the latency of per packet. The maximum +value shouldn't be larger than xs->max_tx_budget. + XDP_STATISTICS getsockopt ------------------------- diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index ce587a225661..b5a3e37da8db 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -61,6 +61,7 @@ struct xdp_sock { XSK_BOUND, XSK_UNBOUND, } state; + struct sk_buff **skb_batch; struct xsk_queue *tx ____cacheline_aligned_in_smp; struct list_head tx_list; @@ -70,6 +71,7 @@ struct xdp_sock { * preventing other XSKs from being starved. */ u32 tx_budget_spent; + u32 generic_xmit_batch; /* Statistics */ u64 rx_dropped; diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h index 23a062781468..44cb72cd328e 100644 --- a/include/uapi/linux/if_xdp.h +++ b/include/uapi/linux/if_xdp.h @@ -80,6 +80,7 @@ struct xdp_mmap_offsets { #define XDP_STATISTICS 7 #define XDP_OPTIONS 8 #define XDP_MAX_TX_SKB_BUDGET 9 +#define XDP_GENERIC_XMIT_BATCH 10 struct xdp_umem_reg { __u64 addr; /* Start of packet data area */ diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 9c3acecc14b1..7a149f4ac273 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -1122,6 +1122,7 @@ static int xsk_release(struct socket *sock) xskq_destroy(xs->tx); xskq_destroy(xs->fq_tmp); xskq_destroy(xs->cq_tmp); + kfree(xs->skb_batch); sock_orphan(sk); sock->sk = NULL; @@ -1456,6 +1457,37 @@ static int xsk_setsockopt(struct socket *sock, int level, int optname, WRITE_ONCE(xs->max_tx_budget, budget); return 0; } + case XDP_GENERIC_XMIT_BATCH: + { + unsigned int batch, batch_alloc_len; + struct sk_buff **new; + + if (optlen != sizeof(batch)) + return -EINVAL; + if (copy_from_sockptr(&batch, optval, sizeof(batch))) + return -EFAULT; + if (batch > xs->max_tx_budget) + return -EACCES; + + mutex_lock(&xs->mutex); + if (!batch) { + kfree(xs->skb_batch); + xs->generic_xmit_batch = 0; + goto out; + } + batch_alloc_len = sizeof(struct sk_buff *) * batch; + new = kmalloc(batch_alloc_len, GFP_KERNEL); + if (!new) + return -ENOMEM; + if (xs->skb_batch) + kfree(xs->skb_batch); + + xs->skb_batch = new; + xs->generic_xmit_batch = batch; +out: + mutex_unlock(&xs->mutex); + return 0; + } default: break; } diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h index 23a062781468..44cb72cd328e 100644 --- a/tools/include/uapi/linux/if_xdp.h +++ b/tools/include/uapi/linux/if_xdp.h @@ -80,6 +80,7 @@ struct xdp_mmap_offsets { #define XDP_STATISTICS 7 #define XDP_OPTIONS 8 #define XDP_MAX_TX_SKB_BUDGET 9 +#define XDP_GENERIC_XMIT_BATCH 10 struct xdp_umem_reg { __u64 addr; /* Start of packet data area */ -- 2.41.3