On 09/14/2018 08:43 AM, Paolo Abeni wrote:
> This is the RX counter part of commit bec1f6f69736 ("udp: generate gso
> with UDP_SEGMENT"). When UDP_SEGMENT is enabled, such socket is also
> eligible for GRO in the rx path: UDP segments directed to such socket
> are assembled into a larger GSO_UDP_L4 packet.
>
> The core UDP GRO support is enabled/updated on setsockopt(UDP_SEGMENT) and
> disabled, if needed at socket destruction time.
>
> Initial benchmark numbers:
>
> Before:
> udp rx: 1079 MB/s 769065 calls/s
>
> After:
> udp rx: 1466 MB/s 24877 calls/s
Are you sure the data is actually fully copied to user space ?
tools/testing/selftests/net/udpgso_bench_rx.c
uses :
static char rbuf[ETH_DATA_LEN];
/* MSG_TRUNC will make return value full datagram length */
ret = recv(fd, rbuf, len, MSG_TRUNC | MSG_DONTWAIT);
So you need to change this program.
Also, GRO reception would mean that userspace can retrieve,
not only full bytes of X datagrams, but also the gso_size (or length of
individual datagrams)
You can not know the size of the packets in advance, the sender will decide.
