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. 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 | 186 +++++++++++++------------ tools/testing/selftests/net/tcp_mmap.c | 63 +++++---- 3 files changed, 139 insertions(+), 118 deletions(-) -- 2.17.0.484.g0c8726318c-goog
