From: Jesper Dangaard Brouer <brouer@redhat•com>
To: "Björn Töpel" <bjorn.topel@gmail•com>
Cc: magnus.karlsson@intel•com, alexander.h.duyck@intel•com,
alexander.duyck@gmail•com, john.fastabend@gmail•com, ast@fb•com,
willemdebruijn.kernel@gmail•com, daniel@iogearbox•net,
mst@redhat•com, netdev@vger•kernel.org,
michael.lundkvist@ericsson•com, jesse.brandeburg@intel•com,
anjali.singhai@intel•com, qi.z.zhang@intel•com,
"Björn Töpel" <bjorn.topel@intel•com>,
brouer@redhat•com
Subject: Re: [PATCH bpf-next v3 15/15] samples/bpf: sample application and documentation for AF_XDP sockets
Date: Wed, 2 May 2018 22:59:03 +0200 [thread overview]
Message-ID: <20180502225903.39180be8@redhat.com> (raw)
In-Reply-To: <20180502110136.3738-16-bjorn.topel@gmail.com>
On Wed, 2 May 2018 13:01:36 +0200 Björn Töpel <bjorn.topel@gmail•com> wrote:
> +static void rx_drop(struct xdpsock *xsk)
> +{
> + struct xdp_desc descs[BATCH_SIZE];
> + unsigned int rcvd, i;
> +
> + rcvd = xq_deq(&xsk->rx, descs, BATCH_SIZE);
> + if (!rcvd)
> + return;
> +
> + for (i = 0; i < rcvd; i++) {
> + u32 idx = descs[i].idx;
> +
> + lassert(idx < NUM_FRAMES);
> +#if DEBUG_HEXDUMP
> + char *pkt;
> + char buf[32];
> +
> + pkt = xq_get_data(xsk, idx, descs[i].offset);
> + sprintf(buf, "idx=%d", idx);
> + hex_dump(pkt, descs[i].len, buf);
> +#endif
> + }
> +
> + xsk->rx_npkts += rcvd;
> +
> + umem_fill_to_kernel_ex(&xsk->umem->fq, descs, rcvd);
> +}
I would really like to see an option that can enable reading the
data/memory in the packet. Else the test is rather fake...
I hacked it myself manually to read first u32.
- Before: 10,771,083 pps
- After: 9,430,741 pps
The slowdown is not as big as I expected, which is good :-)
With perf stat I can see more LLC-load's, but not misses. It is not
getting registered as a cache-miss that I read data on the remote CPPU.
p.s. these tests are with mlx5 (which only have XDP_REDIRECT RX-side).
- -
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
Before:
sudo ~/perf stat -C3 -e L1-icache-load-misses -e cycles -e instructions -e cache-misses -e cache-references -e LLC-store-misses -e LLC-store -e LLC-load-misses -e LLC-load -r 3 sleep 1
Performance counter stats for 'CPU(s) 3' (3 runs):
200,020 L1-icache-load-misses ( +- 0.76% ) (33.31%)
3,920,754,587 cycles ( +- 0.14% ) (44.50%)
3,062,308,209 instructions # 0.78 insn per cycle ( +- 0.28% ) (55.65%)
823 cache-misses # 0.011 % of all cache refs ( +- 70.81% ) (66.74%)
7,587,132 cache-references ( +- 0.48% ) (77.83%)
0 LLC-store-misses (77.83%)
384,401 LLC-store ( +- 2.97% ) (77.83%)
15 LLC-load-misses # 0.00% of all LL-cache hits ( +-100.00% ) (22.17%)
3,192,312 LLC-load ( +- 0.35% ) (22.17%)
1.001199221 seconds time elapsed ( +- 0.00% )
After:
$ sudo ~/perf stat -C3 -e L1-icache-load-misses -e cycles -e instructions -e cache-misses -e cache-references -e LLC-store-misses -e LLC-store -e LLC-load-misses -e LLC-load -r 3 sleep 1
Performance counter stats for 'CPU(s) 3' (3 runs):
154,921 L1-icache-load-misses ( +- 3.88% ) (33.31%)
3,924,791,213 cycles ( +- 0.10% ) (44.50%)
2,930,116,185 instructions # 0.75 insn per cycle ( +- 0.33% ) (55.65%)
342 cache-misses # 0.002 % of all cache refs ( +- 65.52% ) (66.74%)
15,810,892 cache-references ( +- 0.13% ) (77.83%)
0 LLC-store-misses (77.83%)
925,544 LLC-store ( +- 2.33% ) (77.83%)
155 LLC-load-misses # 0.00% of all LL-cache hits ( +- 67.22% ) (22.17%)
12,791,264 LLC-load ( +- 0.04% ) (22.17%)
1.001206058 seconds time elapsed ( +- 0.00% )
next prev parent reply other threads:[~2018-05-02 20:59 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-02 11:01 [PATCH bpf-next v3 00/15] Introducing AF_XDP support Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 01/15] net: initial AF_XDP skeleton Björn Töpel
2018-05-23 22:50 ` Stephen Hemminger
2018-05-24 6:38 ` Björn Töpel
2018-05-24 17:57 ` Alexei Starovoitov
2018-05-02 11:01 ` [PATCH bpf-next v3 02/15] xsk: add user memory registration support sockopt Björn Töpel
2018-05-04 12:34 ` Daniel Borkmann
2018-05-02 11:01 ` [PATCH bpf-next v3 03/15] xsk: add umem fill queue support and mmap Björn Töpel
2018-05-04 12:49 ` Daniel Borkmann
2018-05-02 11:01 ` [PATCH bpf-next v3 04/15] xsk: add Rx queue setup and mmap support Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 05/15] xsk: add support for bind for Rx Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 06/15] xsk: add Rx receive functions and poll support Björn Töpel
2018-05-04 12:59 ` Daniel Borkmann
2018-05-22 7:42 ` Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 07/15] bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP Björn Töpel
2018-10-08 15:31 ` Eric Dumazet
2018-10-08 16:05 ` Björn Töpel
2018-10-08 16:52 ` Björn Töpel
2018-10-08 16:55 ` Eric Dumazet
2018-10-08 17:04 ` Björn Töpel
2018-10-08 17:40 ` [PATCH bpf] xsk: do not call synchronize_net() under RCU read lock Björn Töpel
2018-10-09 0:30 ` Song Liu
2018-10-11 8:22 ` Daniel Borkmann
2018-05-02 11:01 ` [PATCH bpf-next v3 08/15] xsk: wire up XDP_DRV side of AF_XDP Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 09/15] xsk: wire up XDP_SKB " Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 10/15] xsk: add umem completion queue support and mmap Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 11/15] xsk: add Tx queue setup and mmap support Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 12/15] dev: packet: make packet_direct_xmit a common function Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 13/15] xsk: support for Tx Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 14/15] xsk: statistics support Björn Töpel
2018-05-02 11:01 ` [PATCH bpf-next v3 15/15] samples/bpf: sample application and documentation for AF_XDP sockets Björn Töpel
2018-05-02 20:59 ` Jesper Dangaard Brouer [this message]
2018-05-03 13:55 ` [PATCH bpf-next v3 00/15] Introducing AF_XDP support Willem de Bruijn
2018-05-03 15:07 ` David Miller
2018-05-03 22:49 ` Daniel Borkmann
2018-05-03 23:38 ` Alexei Starovoitov
2018-05-04 11:22 ` Magnus Karlsson
2018-05-05 0:34 ` Alexei Starovoitov
2018-05-07 9:13 ` Magnus Karlsson
2018-05-07 13:09 ` Jesper Dangaard Brouer
2018-05-07 19:47 ` Björn Töpel
2018-05-17 6:46 ` Björn Töpel
2018-05-18 3:38 ` Alexei Starovoitov
2018-05-18 13:43 ` Daniel Borkmann
2018-05-18 15:18 ` Björn Töpel
2018-05-18 16:17 ` Daniel Borkmann
2018-05-18 16:32 ` Björn Töpel
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