From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57608 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752479AbcLHGVj (ORCPT ); Thu, 8 Dec 2016 01:21:39 -0500 Subject: Patch "gro_cells: mark napi struct as not busy poll candidates" has been added to the 4.8-stable tree To: edumazet@google.com, davem@davemloft.net, ebiederm@xmission.com, gregkh@linuxfoundation.org, rolf.neugebauer@docker.com, xiyou.wangcong@gmail.com Cc: , From: Date: Thu, 08 Dec 2016 07:20:47 +0100 Message-ID: <148117804782109@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled gro_cells: mark napi struct as not busy poll candidates to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: gro_cells-mark-napi-struct-as-not-busy-poll-candidates.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Thu Dec 8 07:19:12 CET 2016 From: Eric Dumazet Date: Mon, 14 Nov 2016 16:28:42 -0800 Subject: gro_cells: mark napi struct as not busy poll candidates From: Eric Dumazet [ Upstream commit e88a2766143a27bfe6704b4493b214de4094cf29 ] Rolf Neugebauer reported very long delays at netns dismantle. Eric W. Biederman was kind enough to look at this problem and noticed synchronize_net() occurring from netif_napi_del() that was added in linux-4.5 Busy polling makes no sense for tunnels NAPI. If busy poll is used for sessions over tunnels, the poller will need to poll the physical device queue anyway. netif_tx_napi_add() could be used here, but function name is misleading, and renaming it is not stable material, so set NAPI_STATE_NO_BUSY_POLL bit directly. This will avoid inserting gro_cells napi structures in napi_hash[] and avoid the problematic synchronize_net() (per possible cpu) that Rolf reported. Fixes: 93d05d4a320c ("net: provide generic busy polling to all NAPI drivers") Signed-off-by: Eric Dumazet Reported-by: Rolf Neugebauer Reported-by: Eric W. Biederman Acked-by: Cong Wang Tested-by: Rolf Neugebauer Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- include/net/gro_cells.h | 3 +++ 1 file changed, 3 insertions(+) --- a/include/net/gro_cells.h +++ b/include/net/gro_cells.h @@ -68,6 +68,9 @@ static inline int gro_cells_init(struct struct gro_cell *cell = per_cpu_ptr(gcells->cells, i); __skb_queue_head_init(&cell->napi_skbs); + + set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state); + netif_napi_add(dev, &cell->napi, gro_cell_poll, 64); napi_enable(&cell->napi); } Patches currently in stable-queue which might be from edumazet@google.com are queue-4.8/ipv4-fix-memory-leak-in-exception-case-for-splitting-tries.patch queue-4.8/virtio-net-add-a-missing-synchronize_net.patch queue-4.8/gro_cells-mark-napi-struct-as-not-busy-poll-candidates.patch queue-4.8/udplite-call-proper-backlog-handlers.patch queue-4.8/ip6_offload-check-segs-for-null-in-ipv6_gso_segment.patch queue-4.8/ipv4-restore-fib_trie_flush_external-function-and-fix-call-ordering.patch queue-4.8/net-dccp-fix-use-after-free-in-dccp_invalid_packet.patch queue-4.8/net-avoid-signed-overflows-for-so_-snd-rcv-bufforce.patch queue-4.8/packet-fix-race-condition-in-packet_set_ring.patch