From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot0-f198.google.com (mail-ot0-f198.google.com [74.125.82.198]) by kanga.kvack.org (Postfix) with ESMTP id 5E6176B0005 for ; Sun, 29 Apr 2018 21:34:21 -0400 (EDT) Received: by mail-ot0-f198.google.com with SMTP id 106-v6so5804848otg.22 for ; Sun, 29 Apr 2018 18:34:21 -0700 (PDT) Received: from shards.monkeyblade.net (shards.monkeyblade.net. [184.105.139.130]) by mx.google.com with ESMTPS id 63-v6si2245307otp.133.2018.04.29.18.34.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 29 Apr 2018 18:34:19 -0700 (PDT) Date: Sun, 29 Apr 2018 21:34:17 -0400 (EDT) Message-Id: <20180429.213417.1622456092178936722.davem@davemloft.net> Subject: Re: [PATCH v4 net-next 0/2] tcp: mmap: rework zerocopy receive From: David Miller In-Reply-To: <20180427155809.79094-1-edumazet@google.com> References: <20180427155809.79094-1-edumazet@google.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: edumazet@google.com Cc: netdev@vger.kernel.org, luto@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ka-cheong.poon@oracle.com, eric.dumazet@gmail.com From: Eric Dumazet Date: Fri, 27 Apr 2018 08:58:07 -0700 > 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. Looks great, series applied, thanks Eric.