From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 644356B0003 for ; Fri, 27 Apr 2018 11:58:20 -0400 (EDT) Received: by mail-wr0-f198.google.com with SMTP id u13-v6so1771615wre.1 for ; Fri, 27 Apr 2018 08:58:20 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id f7-v6sor757114wrf.63.2018.04.27.08.58.18 for (Google Transport Security); Fri, 27 Apr 2018 08:58:18 -0700 (PDT) From: Eric Dumazet Subject: [PATCH v4 net-next 0/2] tcp: mmap: rework zerocopy receive Date: Fri, 27 Apr 2018 08:58:07 -0700 Message-Id: <20180427155809.79094-1-edumazet@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: "David S . Miller" Cc: netdev , Andy Lutomirski , linux-kernel , linux-mm , Ka-Cheong Poon , Eric Dumazet , Eric Dumazet 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 getsockopt() operation and changes mmap() behavior. Second patch changes tcp_mmap reference program. v4: tcp mmap() support depends on CONFIG_MMU, as kbuild bot told us. v3: change TCP_ZEROCOPY_RECEIVE to be a getsockopt() option instead of setsockopt(), feedback from Ka-Cheon Poon 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. 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/af_inet.c | 2 + net/ipv4/tcp.c | 196 +++++++++++++------------ net/ipv6/af_inet6.c | 2 + tools/testing/selftests/net/tcp_mmap.c | 64 ++++---- 5 files changed, 154 insertions(+), 118 deletions(-) -- 2.17.0.441.gb46fe60e1d-goog