Re: [PATCH v2 net-next 0/2] tcp: mmap: rework zerocopy receive

From: Soheil Hassas Yeganeh
Date: Wed Apr 25 2018 - 21:21:30 EST


On Wed, Apr 25, 2018 at 5:43 PM, Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
> syzbot reported a lockdep issue caused by tcp mmap() support.
>
> I implemented Andy Lutomirski nice suggestions to resolve the
> issue and increase scalability as well.
>
> First patch is adding a new setsockopt() operation and changes mmap()
> behavior.
>
> Second patch changes tcp_mmap reference program.
>
> v2:
> Added a missing page align of zc->length in tcp_zerocopy_receive()
> Properly clear zc->recv_skip_hint in case user request was completed.

Acked-by: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>

Thank you Eric for the nice redesign!

> Eric Dumazet (2):
> tcp: add TCP_ZEROCOPY_RECEIVE support for zerocopy receive
> selftests: net: tcp_mmap must use TCP_ZEROCOPY_RECEIVE
>
> include/uapi/linux/tcp.h | 8 ++
> net/ipv4/tcp.c | 189 +++++++++++++------------
> tools/testing/selftests/net/tcp_mmap.c | 63 +++++----
> 3 files changed, 142 insertions(+), 118 deletions(-)
>
> --
> 2.17.0.441.gb46fe60e1d-goog
>