[PATCH net-next v3 00/32] Replacing net_mutex with rw_semaphore

Kirill Tkhai
2018-02-13T09:26:03Z

Hi,

this is the third version of the patchset introducing net_sem
instead of net_mutex. The patchset adds net_sem in addition
to net_mutex and allows pernet_operations to be "async". This
flag means, the pernet_operations methods are safe to be
executed with any other pernet_operations (un)initializing
another net.

If there are only async pernet_operations in the system,
net_mutex is not used either for setup_net() or for cleanup_net().

The pernet_operations converted in this patchset allow
to create minimal .config to have network working, and
the changes improve the performance like you may see
below:

%for i in {1..10000}; do unshare -n bash -c exit; done

*before*
real 1m40,377s
user 0m9,672s
sys 0m19,928s

*after*
real 0m17,007s
user 0m5,311s
sys 0m11,779

(5.8 times faster)

In the future, when all pernet_operations become async,
we'll just remove this "async" field tree-wide.

All the new logic is concentrated in patches [1-5/32].
The rest of patches converts specific operations:
review, rationale of they can be converted, and setting
of async flag.

Kirill

v3: Improved patches descriptions. Added comment into [5/32].
Added [32/32] converting netlink_tap_net_ops (new pernet operations
introduced in 2018).

v2: Single patch -> patchset with rationale of every conversion

---

Kirill Tkhai (32):
net: Assign net to net_namespace_list in setup_net()
net: Cleanup in copy_net_ns()
net: Introduce net_sem for protection of pernet_list
net: Move mutex_unlock() in cleanup_net() up
net: Allow pernet_operations to be executed in parallel
net: Convert proc_net_ns_ops
net: Convert net_ns_ops methods
net: Convert sysctl_pernet_ops
net: Convert netfilter_net_ops
net: Convert nf_log_net_ops
net: Convert net_inuse_ops
net: Convert net_defaults_ops
net: Convert netlink_net_ops
net: Convert rtnetlink_net_ops
net: Convert audit_net_ops
net: Convert uevent_net_ops
net: Convert proto_net_ops
net: Convert pernet_subsys ops, registered via net_dev_init()
net: Convert fib_* pernet_operations, registered via subsys_initcall
net: Convert subsys_initcall() registered pernet_operations from net/sched
net: Convert genl_pernet_ops
net: Convert wext_pernet_ops
net: Convert sysctl_core_ops
net: Convert pernet_subsys, registered from inet_init()
net: Convert unix_net_ops
net: Convert packet_net_ops
net: Convert ipv4_sysctl_ops
net: Convert addrconf_ops
net: Convert loopback_net_ops
net: Convert default_device_ops
net: Convert diag_net_ops
net: Convert netlink_tap_net_ops

drivers/net/loopback.c | 1
fs/proc/proc_net.c | 1
include/linux/rtnetlink.h | 1
include/net/net_namespace.h | 6 +++
kernel/audit.c | 1
lib/kobject_uevent.c | 1
net/core/dev.c | 2 +
net/core/fib_notifier.c | 1
net/core/fib_rules.c | 1
net/core/net-procfs.c | 2 +
net/core/net_namespace.c | 95 +++++++++++++++++++++++++------------------
net/core/rtnetlink.c | 5 +-
net/core/sock.c | 2 +
net/core/sock_diag.c | 1
net/core/sysctl_net_core.c | 1
net/ipv4/af_inet.c | 2 +
net/ipv4/arp.c | 1
net/ipv4/devinet.c | 1
net/ipv4/fib_frontend.c | 1
net/ipv4/icmp.c | 1
net/ipv4/igmp.c | 1
net/ipv4/ip_fragment.c | 1
net/ipv4/ipmr.c | 1
net/ipv4/ping.c | 1
net/ipv4/proc.c | 1
net/ipv4/raw.c | 1
net/ipv4/route.c | 4 ++
net/ipv4/sysctl_net_ipv4.c | 1
net/ipv4/tcp_ipv4.c | 2 +
net/ipv4/tcp_metrics.c | 1
net/ipv4/udp.c | 1
net/ipv4/udplite.c | 1
net/ipv4/xfrm4_policy.c | 1
net/ipv6/addrconf.c | 1
net/netfilter/core.c | 1
net/netfilter/nf_log.c | 1
net/netlink/af_netlink.c | 2 +
net/netlink/genetlink.c | 1
net/packet/af_packet.c | 1
net/sched/act_api.c | 1
net/sched/sch_api.c | 1
net/sysctl_net.c | 1
net/unix/af_unix.c | 1
net/wireless/wext-core.c | 1
net/xfrm/xfrm_policy.c | 1
45 files changed, 116 insertions(+), 41 deletions(-)