VPP typically works best if configured with a relatively small number of buffers. On the other hand, nsim can induce a large amount of delay, so the buffers cannot be used to temporarily store the data.
Florin > On Jan 29, 2019, at 3:19 AM, Raj <rajlistu...@gmail.com> wrote: > > Hello all, > > While I was browsing through the nsim code (plugins/nsim), > > in nsim_inline() we are copying the packet data to ep->data like below > > clib_memcpy (ep->data, vlib_buffer_get_current (b[0]), > ep->current_length); > > and in nsim_input.c the same packet is transferring to TX > > clib_memcpy (b0->data, ep->data, ep->current_length) > > The data is defined in the below structure > typedef struct > { > f64 tx_time; > u32 tx_sw_if_index; > u32 current_length; > CLIB_CACHE_LINE_ALIGN_MARK (pad); > u8 data[WHEEL_ENTRY_DATA_SIZE]; > } nsim_wheel_entry_t; > > I am just wondering if there is any special reason why 'data' as such > is copied here from the vlib buffer to the wheel buffer, instead of > using the pointer(copying just the address), and thus avoiding a > packet copy? > > Is it not possible to keep the packet in vlib buffer itself till it > is transmitted NIC/DPDK TX after a delay? > > Thanks and Regards, > > Raj > -=-=-=-=-=-=-=-=-=-=-=- > Links: You receive all messages sent to this group. > > View/Reply Online (#12040): https://lists.fd.io/g/vpp-dev/message/12040 > Mute This Topic: https://lists.fd.io/mt/29581029/675152 > Group Owner: vpp-dev+ow...@lists.fd.io > Unsubscribe: https://lists.fd.io/g/vpp-dev/unsub [fcoras.li...@gmail.com] > -=-=-=-=-=-=-=-=-=-=-=-
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