Ahmed S. Darwish 29cbcd8582 net: sched: Remove Qdisc::running sequence counter ... The Qdisc::running sequence counter has two uses: 1. Reliably reading qdisc's tc statistics while the qdisc is running (a seqcount read/retry loop at gnet_stats_add_basic()). 2. As a flag, indicating whether the qdisc in question is running (without any retry loops). For the first usage, the Qdisc::running sequence counter write section, qdisc_run_begin() => qdisc_run_end(), covers a much wider area than what is actually needed: the raw qdisc's bstats update. A u64_stats sync point was thus introduced (in previous commits) inside the bstats structure itself. A local u64_stats write section is then started and stopped for the bstats updates. Use that u64_stats sync point mechanism for the bstats read/retry loop at gnet_stats_add_basic(). For the second qdisc->running usage, a __QDISC_STATE_RUNNING bit flag, accessed with atomic bitops, is sufficient. Using a bit flag instead of a sequence counter at qdisc_run_begin/end() and qdisc_is_running() leads to the SMP barriers implicitly added through raw_read_seqcount() and write_seqcount_begin/end() getting removed. All call sites have been surveyed though, and no required ordering was identified. Now that the qdisc->running sequence counter is no longer used, remove it. Note, using u64_stats implies no sequence counter protection for 64-bit architectures. This can lead to the qdisc tc statistics "packets" vs. "bytes" values getting out of sync on rare occasions. The individual values will still be valid. Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>		2021-10-18 12:54:41 +01:00
..
bpf_sk_storage.c
datagram.c
datagram.h
dev_addr_lists.c
dev_ioctl.c
dev.c
devlink.c
drop_monitor.c
dst_cache.c
dst.c
failover.c
fib_notifier.c
fib_rules.c
filter.c
flow_dissector.c
flow_offload.c
gen_estimator.c	net: sched: Remove Qdisc::running sequence counter	2021-10-18 12:54:41 +01:00
gen_stats.c	net: sched: Remove Qdisc::running sequence counter	2021-10-18 12:54:41 +01:00
gro_cells.c
hwbm.c
link_watch.c
lwt_bpf.c
lwtunnel.c
Makefile
neighbour.c	net, neigh: Reject creating NUD_PERMANENT with NTF_MANAGED entries	2021-10-14 19:16:21 -07:00
net_namespace.c
net-procfs.c
net-sysfs.c
net-sysfs.h
net-traces.c
netclassid_cgroup.c
netevent.c
netpoll.c
netprio_cgroup.c
of_net.c
page_pool.c	page_pool: disable dma mapping support for 32-bit arch with 64-bit DMA	2021-10-15 10:54:20 +01:00
pktgen.c
ptp_classifier.c
request_sock.c
rtnetlink.c	net: make use of helper netif_is_bridge_master()	2021-10-16 15:02:56 +01:00
scm.c
secure_seq.c
selftests.c
skbuff.c
skmsg.c
sock_diag.c
sock_map.c
sock_reuseport.c
sock.c
stream.c	net: stream: don't purge sk_error_queue in sk_stream_kill_queues()	2021-10-16 09:06:09 +01:00
sysctl_net_core.c
timestamping.c
tso.c
utils.c
xdp.c