linux_dsm_epyc7002/net/core
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
..
datagram.c net: simplify sock_poll_wait 2018-07-30 09:10:25 -07:00
dev_addr_lists.c net: change the comment of dev_mc_init 2018-04-19 12:58:20 -04:00
dev_ioctl.c net: remove redundant input checks in SIOCSIFTXQLEN case of dev_ifsioc 2018-07-24 11:36:15 -07:00
dev.c net: allow to call netif_reset_xps_queues() under cpus_read_lock 2018-08-09 14:25:06 -07:00
devlink.c devlink: Add generic parameters region_snapshot 2018-07-12 17:37:13 -07:00
drop_monitor.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
dst_cache.c net: core: dst_cache_set_ip6: Rename 'addr' parameter to 'saddr' for consistency 2018-03-05 12:52:45 -05:00
dst.c netfilter: nf_tables: add tunnel support 2018-08-03 21:12:12 +02:00
ethtool.c net: Add TLS RX offload feature 2018-07-16 00:12:09 -07:00
failover.c net: Introduce generic failover module 2018-05-28 22:59:54 -04:00
fib_notifier.c net: Fix fib notifer to return errno 2018-03-29 14:10:30 -04:00
fib_rules.c fib_rules: NULL check before kfree is not needed 2018-07-30 09:44:06 -07:00
filter.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-08-07 11:02:05 -07:00
flow_dissector.c flow_dissector: allow dissection of tunnel options from metadata 2018-08-07 12:22:14 -07:00
gen_estimator.c net_sched: gen_estimator: fix broken estimators based on percpu stats 2018-02-23 12:35:46 -05:00
gen_stats.c gen_stats: Fix netlink stats dumping in the presence of padding 2018-07-04 14:44:45 +09:00
gro_cells.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hwbm.c net: hwbm: Fix unbalanced spinlock in error case 2016-05-25 12:35:09 -07:00
link_watch.c net: link_watch: mark bonding link events urgent 2018-01-23 19:43:30 -05:00
lwt_bpf.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2018-08-07 11:02:05 -07:00
lwtunnel.c ipv6: sr: define core operations for seg6local lightweight tunnel 2017-08-07 14:16:22 -07:00
Makefile net: Introduce generic failover module 2018-05-28 22:59:54 -04:00
neighbour.c net: remove blank lines at end of file 2018-07-24 14:10:43 -07:00
net_namespace.c net: create reusable function for getting ownership info of sysfs inodes 2018-07-20 23:44:36 -07:00
net-procfs.c proc: introduce proc_create_net{,_data} 2018-05-16 07:24:30 +02:00
net-sysfs.c net: allow to call netif_reset_xps_queues() under cpus_read_lock 2018-08-09 14:25:06 -07:00
net-sysfs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
net-traces.c net/ipv6: Udate fib6_table_lookup tracepoint 2018-05-24 23:01:15 -04:00
netclassid_cgroup.c cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS 2017-07-21 11:14:51 -04:00
netevent.c netevent: remove automatic variable in register_netevent_notifier() 2015-05-31 00:03:21 -07:00
netpoll.c netpoll: Use lockdep to assert IRQs are disabled/enabled 2017-11-08 11:13:54 +01:00
netprio_cgroup.c net: remove duplicate includes 2017-12-13 13:18:46 -05:00
page_pool.c net/page_pool: Fix inconsistent lock state warning 2018-07-19 23:23:01 -07:00
pktgen.c Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next 2018-07-27 09:33:37 -07:00
ptp_classifier.c ptp: Change ptp_class to a proper bitmask 2015-11-03 11:08:22 -05:00
request_sock.c ipv4: Namespaceify tcp_max_syn_backlog knob 2016-12-29 11:38:31 -05:00
rtnetlink.c net: report invalid mtu value via netlink extack 2018-07-29 12:57:26 -07:00
scm.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h> 2017-03-02 08:42:29 +01:00
secure_seq.c tcp: Namespaceify sysctl_tcp_timestamps 2017-06-08 10:53:29 -04:00
skbuff.c net: modify skb_rbtree_purge to return the truesize of all purged skbs. 2018-08-05 17:16:46 -07:00
sock_diag.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
sock_reuseport.c soreuseport: fix mem leak in reuseport_add_sock() 2018-02-02 19:47:03 -05:00
sock.c net: avoid unnecessary sock_flag() check when enable timestamp 2018-08-06 10:42:48 -07:00
stream.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
sysctl_net_core.c headers: untangle kmemleak.h from mm.h 2018-04-05 21:36:27 -07:00
timestamping.c net: skb_defer_rx_timestamp should check for phydev before setting up classify 2015-07-09 14:17:15 -07:00
tso.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
utils.c net: Remove some unneeded semicolon 2018-08-04 13:05:39 -07:00
xdp.c Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net 2018-08-02 10:55:32 -07:00