From 123e8da1d33042a83cedb530fb5efd64f32ce594 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Wed, 26 Jun 2019 17:35:27 +0300 Subject: [PATCH] xsk: Change the default frame size to 4096 and allow controlling it The typical XDP memory scheme is one packet per page. Change the AF_XDP frame size in libbpf to 4096, which is the page size on x86, to allow libbpf to be used with the drivers with the packet-per-page scheme. Add a command line option -f to xdpsock to allow to specify a custom frame size. Signed-off-by: Maxim Mikityanskiy Signed-off-by: Tariq Toukan Acked-by: Saeed Mahameed Signed-off-by: Daniel Borkmann --- samples/bpf/xdpsock_user.c | 44 ++++++++++++++++++++++++-------------- tools/lib/bpf/xsk.h | 2 +- 2 files changed, 29 insertions(+), 17 deletions(-) diff --git a/samples/bpf/xdpsock_user.c b/samples/bpf/xdpsock_user.c index 0f5eb0d7f2df..93eaaf7239b2 100644 --- a/samples/bpf/xdpsock_user.c +++ b/samples/bpf/xdpsock_user.c @@ -68,6 +68,7 @@ static int opt_queue; static int opt_poll; static int opt_interval = 1; static u32 opt_xdp_bind_flags; +static int opt_xsk_frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE; static __u32 prog_id; struct xsk_umem_info { @@ -276,6 +277,12 @@ static size_t gen_eth_frame(struct xsk_umem_info *umem, u64 addr) static struct xsk_umem_info *xsk_configure_umem(void *buffer, u64 size) { struct xsk_umem_info *umem; + struct xsk_umem_config cfg = { + .fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS, + .comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS, + .frame_size = opt_xsk_frame_size, + .frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM, + }; int ret; umem = calloc(1, sizeof(*umem)); @@ -283,7 +290,7 @@ static struct xsk_umem_info *xsk_configure_umem(void *buffer, u64 size) exit_with_error(errno); ret = xsk_umem__create(&umem->umem, buffer, size, &umem->fq, &umem->cq, - NULL); + &cfg); if (ret) exit_with_error(-ret); @@ -323,11 +330,9 @@ static struct xsk_socket_info *xsk_configure_socket(struct xsk_umem_info *umem) &idx); if (ret != XSK_RING_PROD__DEFAULT_NUM_DESCS) exit_with_error(-ret); - for (i = 0; - i < XSK_RING_PROD__DEFAULT_NUM_DESCS * - XSK_UMEM__DEFAULT_FRAME_SIZE; - i += XSK_UMEM__DEFAULT_FRAME_SIZE) - *xsk_ring_prod__fill_addr(&xsk->umem->fq, idx++) = i; + for (i = 0; i < XSK_RING_PROD__DEFAULT_NUM_DESCS; i++) + *xsk_ring_prod__fill_addr(&xsk->umem->fq, idx++) = + i * opt_xsk_frame_size; xsk_ring_prod__submit(&xsk->umem->fq, XSK_RING_PROD__DEFAULT_NUM_DESCS); @@ -346,6 +351,7 @@ static struct option long_options[] = { {"interval", required_argument, 0, 'n'}, {"zero-copy", no_argument, 0, 'z'}, {"copy", no_argument, 0, 'c'}, + {"frame-size", required_argument, 0, 'f'}, {0, 0, 0, 0} }; @@ -365,8 +371,9 @@ static void usage(const char *prog) " -n, --interval=n Specify statistics update interval (default 1 sec).\n" " -z, --zero-copy Force zero-copy mode.\n" " -c, --copy Force copy mode.\n" + " -f, --frame-size=n Set the frame size (must be a power of two, default is %d).\n" "\n"; - fprintf(stderr, str, prog); + fprintf(stderr, str, prog, XSK_UMEM__DEFAULT_FRAME_SIZE); exit(EXIT_FAILURE); } @@ -377,7 +384,7 @@ static void parse_command_line(int argc, char **argv) opterr = 0; for (;;) { - c = getopt_long(argc, argv, "Frtli:q:psSNn:cz", long_options, + c = getopt_long(argc, argv, "Frtli:q:psSNn:czf:", long_options, &option_index); if (c == -1) break; @@ -420,6 +427,9 @@ static void parse_command_line(int argc, char **argv) case 'F': opt_xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST; break; + case 'f': + opt_xsk_frame_size = atoi(optarg); + break; default: usage(basename(argv[0])); } @@ -432,6 +442,11 @@ static void parse_command_line(int argc, char **argv) usage(basename(argv[0])); } + if (opt_xsk_frame_size & (opt_xsk_frame_size - 1)) { + fprintf(stderr, "--frame-size=%d is not a power of two\n", + opt_xsk_frame_size); + usage(basename(argv[0])); + } } static void kick_tx(struct xsk_socket_info *xsk) @@ -583,8 +598,7 @@ static void tx_only(struct xsk_socket_info *xsk) for (i = 0; i < BATCH_SIZE; i++) { xsk_ring_prod__tx_desc(&xsk->tx, idx + i)->addr - = (frame_nb + i) << - XSK_UMEM__DEFAULT_FRAME_SHIFT; + = (frame_nb + i) * opt_xsk_frame_size; xsk_ring_prod__tx_desc(&xsk->tx, idx + i)->len = sizeof(pkt_data) - 1; } @@ -661,21 +675,19 @@ int main(int argc, char **argv) } ret = posix_memalign(&bufs, getpagesize(), /* PAGE_SIZE aligned */ - NUM_FRAMES * XSK_UMEM__DEFAULT_FRAME_SIZE); + NUM_FRAMES * opt_xsk_frame_size); if (ret) exit_with_error(ret); /* Create sockets... */ - umem = xsk_configure_umem(bufs, - NUM_FRAMES * XSK_UMEM__DEFAULT_FRAME_SIZE); + umem = xsk_configure_umem(bufs, NUM_FRAMES * opt_xsk_frame_size); xsks[num_socks++] = xsk_configure_socket(umem); if (opt_bench == BENCH_TXONLY) { int i; - for (i = 0; i < NUM_FRAMES * XSK_UMEM__DEFAULT_FRAME_SIZE; - i += XSK_UMEM__DEFAULT_FRAME_SIZE) - (void)gen_eth_frame(umem, i); + for (i = 0; i < NUM_FRAMES; i++) + (void)gen_eth_frame(umem, i * opt_xsk_frame_size); } signal(SIGINT, int_exit); diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h index 82ea71a0f3ec..833a6e60d065 100644 --- a/tools/lib/bpf/xsk.h +++ b/tools/lib/bpf/xsk.h @@ -167,7 +167,7 @@ LIBBPF_API int xsk_socket__fd(const struct xsk_socket *xsk); #define XSK_RING_CONS__DEFAULT_NUM_DESCS 2048 #define XSK_RING_PROD__DEFAULT_NUM_DESCS 2048 -#define XSK_UMEM__DEFAULT_FRAME_SHIFT 11 /* 2048 bytes */ +#define XSK_UMEM__DEFAULT_FRAME_SHIFT 12 /* 4096 bytes */ #define XSK_UMEM__DEFAULT_FRAME_SIZE (1 << XSK_UMEM__DEFAULT_FRAME_SHIFT) #define XSK_UMEM__DEFAULT_FRAME_HEADROOM 0