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From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>,
	Eric Dumazet <edumazet@google.com>,
	Michael Chan <michael.chan@broadcom.com>,
	Aviad Krawczyk <aviad.krawczyk@huawei.com>,
	Song Liu <songliubraving@fb.com>,
	Douglas Miller <dougmill@linux.vnet.ibm.com>,
	Yisen Zhuang <yisen.zhuang@huawei.com>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	Harish Patil <harish.patil@cavium.com>,
	Manish Chopra <manish.chopra@cavium.com>,
	Netanel Belgazal <netanel@amazon.com>,
	Solarflare linux maintainers <linux-net-drivers@solarflare.com>,
	Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Subject: [PATCH net 00/11] netpoll: second round of fixes.
Date: Thu, 27 Sep 2018 09:31:50 -0700	[thread overview]
Message-ID: <20180927163201.56609-1-edumazet@google.com> (raw)

As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC).

This capture, showing one ksoftirqd eating all cycles
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.

It seems that all networking drivers that do use NAPI
for their TX completions, should not provide a ndo_poll_controller() :

Most NAPI drivers have netpoll support already handled
in core networking stack, since netpoll_poll_dev()
uses poll_napi(dev) to iterate through registered
NAPI contexts for a device.

First patch is a fix in poll_one_napi().

Then following patches take care of ten drivers.

Eric Dumazet (11):
  netpoll: do not test NAPI_STATE_SCHED in poll_one_napi()
  hinic: remove ndo_poll_controller
  ehea: remove ndo_poll_controller
  net: hns: remove ndo_poll_controller
  virtio_net: remove ndo_poll_controller
  qlcnic: remove ndo_poll_controller
  qlogic: netxen: remove ndo_poll_controller
  net: ena: remove ndo_poll_controller
  sfc: remove ndo_poll_controller
  sfc-falcon: remove ndo_poll_controller
  ibmvnic: remove ndo_poll_controller

 drivers/net/ethernet/amazon/ena/ena_netdev.c  | 22 ---------
 drivers/net/ethernet/hisilicon/hns/hns_enet.c | 18 --------
 .../net/ethernet/huawei/hinic/hinic_main.c    | 20 ---------
 drivers/net/ethernet/ibm/ehea/ehea_main.c     | 14 ------
 drivers/net/ethernet/ibm/ibmvnic.c            | 16 -------
 .../ethernet/qlogic/netxen/netxen_nic_main.c  | 23 ----------
 .../net/ethernet/qlogic/qlcnic/qlcnic_main.c  | 45 -------------------
 drivers/net/ethernet/sfc/efx.c                | 26 -----------
 drivers/net/ethernet/sfc/falcon/efx.c         | 26 -----------
 drivers/net/virtio_net.c                      | 14 ------
 net/core/netpoll.c                            | 20 +--------
 11 files changed, 1 insertion(+), 243 deletions(-)

-- 
2.19.0.605.g01d371f741-goog

             reply	other threads:[~2018-09-27 22:51 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-27 16:31 Eric Dumazet [this message]
2018-09-27 16:31 ` [PATCH net 01/11] netpoll: do not test NAPI_STATE_SCHED in poll_one_napi() Eric Dumazet
2018-09-27 18:25   ` Michael Chan
2018-09-27 18:33     ` Song Liu
2018-09-27 16:31 ` [PATCH net 02/11] hinic: remove ndo_poll_controller Eric Dumazet
2018-09-27 16:31 ` [PATCH net 03/11] ehea: " Eric Dumazet
2018-09-27 16:31 ` [PATCH net 04/11] net: hns: " Eric Dumazet
2018-09-27 16:31 ` [PATCH net 05/11] virtio_net: " Eric Dumazet
2018-09-27 16:31 ` [PATCH net 06/11] qlcnic: " Eric Dumazet
2018-09-27 16:31 ` [PATCH net 07/11] qlogic: netxen: " Eric Dumazet
2018-09-27 16:31 ` [PATCH net 08/11] net: ena: " Eric Dumazet
2018-09-27 16:31 ` [PATCH net 09/11] sfc: " Eric Dumazet
2018-09-28  7:30   ` Bert Kenward
2018-09-27 16:32 ` [PATCH net 10/11] sfc-falcon: " Eric Dumazet
2018-09-28  7:30   ` Bert Kenward
2018-09-27 16:32 ` [PATCH net 11/11] ibmvnic: " Eric Dumazet
2018-09-28 18:14 ` [PATCH net 00/11] netpoll: second round of fixes David Miller

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