From f89bbbe300dad7bc479db535e7822199f98aca30 Mon Sep 17 00:00:00 2001 From: Benoît Ganne Date: Thu, 4 Mar 2021 14:31:03 +0100 Subject: vlib: refactor trajectory trace debug feature MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit trajectory trace has been broken for a while because we used to save the buffer trajectory in a vector pointed to in opaque2. This does not work well when opaque2 is copied (eg. because of a clone) as 2 buffers end up sharing the same vector. This dedicates a full cacheline in the buffer metadata instead when trajectory is compiled in. No dynamic allocation, no sharing, no tears. Type: refactor Change-Id: I6a028ca1b48d38f393a36979e5e452c2dd48ad3f Signed-off-by: Benoît Ganne --- src/plugins/af_xdp/input.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) (limited to 'src/plugins/af_xdp/input.c') diff --git a/src/plugins/af_xdp/input.c b/src/plugins/af_xdp/input.c index 65eee75cb92..da422bdccaf 100644 --- a/src/plugins/af_xdp/input.c +++ b/src/plugins/af_xdp/input.c @@ -130,17 +130,11 @@ af_xdp_device_input_refill (vlib_main_t * vm, /* * Note about headroom: for some reasons, there seem to be a discrepency - * between 0-copy and copy mode: - * - 0-copy: XDP_PACKET_HEADROOM will be added to the user headroom - * - copy: nothing is added to the user headroom - * We privileged 0-copy and set headroom to 0. As XDP_PACKET_HEADROOM == - * sizeof(vlib_buffer_t), data will correctly point to vlib_buffer_t->data. - * In copy mode, we have to add sizeof(vlib_buffer_t) to desc offset during - * refill. + * between 0-copy and copy mode. See + * src/plugins/af_xdp/device.c:af_xdp_create_queue() */ - STATIC_ASSERT (sizeof (vlib_buffer_t) == XDP_PACKET_HEADROOM, "wrong size"); -#define bi2addr(bi) \ - (((bi) << CLIB_LOG2_CACHE_LINE_BYTES) + (copy ? sizeof(vlib_buffer_t) : 0)) +#define bi2addr(bi) \ + (((bi) << CLIB_LOG2_CACHE_LINE_BYTES) + (copy ? XDP_PACKET_HEADROOM : 0)) wrap_around: @@ -218,8 +212,8 @@ af_xdp_device_input_bufs (vlib_main_t * vm, const af_xdp_device_t * ad, const u32 mask = rxq->rx.mask; u32 n = n_rx, *bi = bis, bytes = 0; -#define addr2bi(addr) \ - (((addr) - (copy ? sizeof(vlib_buffer_t) : 0)) >> CLIB_LOG2_CACHE_LINE_BYTES) +#define addr2bi(addr) \ + (((addr) - (copy ? XDP_PACKET_HEADROOM : 0)) >> CLIB_LOG2_CACHE_LINE_BYTES) while (n >= 1) { -- cgit 1.2.3-korg