linux_dsm_epyc7002/drivers/net
Andrei Vagin 4d99f6602c net: allow to call netif_reset_xps_queues() under cpus_read_lock
The definition of static_key_slow_inc() has cpus_read_lock in place. In the
virtio_net driver, XPS queues are initialized after setting the queue:cpu
affinity in virtnet_set_affinity() which is already protected within
cpus_read_lock. Lockdep prints a warning when we are trying to acquire
cpus_read_lock when it is already held.

This patch adds an ability to call __netif_set_xps_queue under
cpus_read_lock().
Acked-by: Jason Wang <jasowang@redhat.com>

============================================
WARNING: possible recursive locking detected
4.18.0-rc3-next-20180703+ #1 Not tainted
--------------------------------------------
swapper/0/1 is trying to acquire lock:
00000000cf973d46 (cpu_hotplug_lock.rw_sem){++++}, at: static_key_slow_inc+0xe/0x20

but task is already holding lock:
00000000cf973d46 (cpu_hotplug_lock.rw_sem){++++}, at: init_vqs+0x513/0x5a0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(cpu_hotplug_lock.rw_sem);
  lock(cpu_hotplug_lock.rw_sem);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

3 locks held by swapper/0/1:
 #0: 00000000244bc7da (&dev->mutex){....}, at: __driver_attach+0x5a/0x110
 #1: 00000000cf973d46 (cpu_hotplug_lock.rw_sem){++++}, at: init_vqs+0x513/0x5a0
 #2: 000000005cd8463f (xps_map_mutex){+.+.}, at: __netif_set_xps_queue+0x8d/0xc60

v2: move cpus_read_lock() out of __netif_set_xps_queue()

Cc: "Nambiar, Amritha" <amritha.nambiar@intel.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Fixes: 8af2c06ff4 ("net-sysfs: Add interface for Rx queue(s) map per Tx queue")

Signed-off-by: Andrei Vagin <avagin@gmail.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-09 14:25:06 -07:00
..
appletalk
arcnet
bonding Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
caif
can Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
dsa net: dsa: rtl8366rb: Support port 4 (WAN) 2018-08-09 14:15:00 -07:00
ethernet ethernet/qlogic: remove unused array msi_tgt_status 2018-08-09 14:16:51 -07:00
fddi
fjes
hamradio
hippi
hyperv hv_netvsc: Add per-cpu ethtool stats for netvsc 2018-07-30 12:35:04 -07:00
ieee802154 ieee802154: hwsim: fix missing unlock on error in hwsim_add_one() 2018-08-08 18:36:49 -07:00
ipvlan
netdevsim Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00
phy net: phy: sftp: print debug message with text, not numbers 2018-08-09 14:19:20 -07:00
plip
ppp ppp: mppe: Remove VLA usage 2018-08-03 12:54:54 -07:00
slip
team team: Publish team_port_get_rcu() 2018-07-11 23:10:19 -07:00
usb net:usb: Use ARRAY_SIZE instead of calculating the array size 2018-08-04 13:23:15 -07:00
vmxnet3
wan Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-05 13:04:31 -07:00
wimax wimax/i2400m: remove redundant variables ack_status, bcf and protocol 2018-07-11 22:54:25 -07:00
wireless wireless-drivers-next patches for 4.19 2018-08-05 17:36:01 -07:00
xen-netback xen-netback: use true and false for boolean values 2018-08-02 14:43:04 -07:00
dummy.c
eql.c
geneve.c
gtp.c gtp: constify nla_policy 2018-07-20 12:33:37 -07:00
ifb.c
Kconfig
LICENSE.SRC
loopback.c
macsec.c
macvlan.c macvlan: Change status when lower device goes down 2018-07-11 23:07:22 -07:00
macvtap.c
Makefile
mdio.c
mii.c
net_failover.c failover: change mtu has RTNL 2018-07-29 12:57:26 -07:00
netconsole.c
nlmon.c
ntb_netdev.c
rionet.c
sb1000.c
Space.c
sungem_phy.c
tap.c
thunderbolt.c
tun.c tun: not use hardcoded mask value 2018-08-04 13:15:11 -07:00
veth.c
virtio_net.c net: allow to call netif_reset_xps_queues() under cpus_read_lock 2018-08-09 14:25:06 -07:00
vrf.c
vsockmon.c
vxlan.c vxlan: fix default fdb entry netlink notify ordering during netdev create 2018-07-22 10:52:37 -07:00
xen-netfront.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00