From bb0247807744dc93407771e13ba20af0b270ca6a Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Fri, 23 Apr 2021 11:27:27 +0200 Subject: bpf, cpumap: Bulk skb using netif_receive_skb_list Rely on netif_receive_skb_list routine to send skbs converted from xdp_frames in cpu_map_kthread_run in order to improve i-cache usage. The proposed patch has been tested running xdp_redirect_cpu bpf sample available in the kernel tree that is used to redirect UDP frames from ixgbe driver to a cpumap entry and then to the networking stack. UDP frames are generated using pktgen. Packets are discarded by the UDP layer. $ xdp_redirect_cpu --cpu --progname xdp_cpu_map0 --dev bpf-next: ~2.35Mpps bpf-next + cpumap skb-list: ~2.72Mpps Rename drops counter in kmem_alloc_drops since now it reports just kmem_cache_alloc_bulk failures Signed-off-by: Lorenzo Bianconi Signed-off-by: Daniel Borkmann Acked-by: Jesper Dangaard Brouer Link: https://lore.kernel.org/bpf/c729f83e5d7482d9329e0f165bdbe5adcefd1510.1619169700.git.lorenzo@kernel.org --- kernel/bpf/cpumap.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'kernel/bpf/cpumap.c') diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 0cf2791d5099..5dd3e866599a 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -27,7 +27,7 @@ #include #include -#include /* netif_receive_skb_core */ +#include /* netif_receive_skb_list */ #include /* eth_type_trans */ /* General idea: XDP packets getting XDP redirected to another CPU, @@ -252,11 +252,12 @@ static int cpu_map_kthread_run(void *data) */ while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) { struct xdp_cpumap_stats stats = {}; /* zero stats */ + unsigned int kmem_alloc_drops = 0, sched = 0; gfp_t gfp = __GFP_ZERO | GFP_ATOMIC; - unsigned int drops = 0, sched = 0; void *frames[CPUMAP_BATCH]; void *skbs[CPUMAP_BATCH]; int i, n, m, nframes; + LIST_HEAD(list); /* Release CPU reschedule checks */ if (__ptr_ring_empty(rcpu->queue)) { @@ -297,7 +298,7 @@ static int cpu_map_kthread_run(void *data) if (unlikely(m == 0)) { for (i = 0; i < nframes; i++) skbs[i] = NULL; /* effect: xdp_return_frame */ - drops += nframes; + kmem_alloc_drops += nframes; } } @@ -305,7 +306,6 @@ static int cpu_map_kthread_run(void *data) for (i = 0; i < nframes; i++) { struct xdp_frame *xdpf = frames[i]; struct sk_buff *skb = skbs[i]; - int ret; skb = __xdp_build_skb_from_frame(xdpf, skb, xdpf->dev_rx); @@ -314,13 +314,13 @@ static int cpu_map_kthread_run(void *data) continue; } - /* Inject into network stack */ - ret = netif_receive_skb_core(skb); - if (ret == NET_RX_DROP) - drops++; + list_add_tail(&skb->list, &list); } + netif_receive_skb_list(&list); + /* Feedback loop via tracepoint */ - trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched, &stats); + trace_xdp_cpumap_kthread(rcpu->map_id, n, kmem_alloc_drops, + sched, &stats); local_bh_enable(); /* resched point, may call do_softirq() */ } -- cgit