linux/net/core
Roopa Prabhu d297653dd6 rtnetlink: fdb dump: optimize by saving last interface markers
fdb dumps spanning multiple skb's currently restart from the first
interface again for every skb. This results in unnecessary
iterations on the already visited interfaces and their fdb
entries. In large scale setups, we have seen this to slow
down fdb dumps considerably. On a system with 30k macs we
see fdb dumps spanning across more than 300 skbs.

To fix the problem, this patch replaces the existing single fdb
marker with three markers: netdev hash entries, netdevs and fdb
index to continue where we left off instead of restarting from the
first netdev. This is consistent with link dumps.

In the process of fixing the performance issue, this patch also
re-implements fix done by
commit 472681d57a ("net: ndo_fdb_dump should report -EMSGSIZE to rtnl_fdb_dump")
(with an internal fix from Wilson Kok) in the following ways:
- change ndo_fdb_dump handlers to return error code instead
of the last fdb index
- use cb->args strictly for dump frag markers and not error codes.
This is consistent with other dump functions.

Below results were taken on a system with 1000 netdevs
and 35085 fdb entries:
before patch:
$time bridge fdb show | wc -l
15065

real    1m11.791s
user    0m0.070s
sys 1m8.395s

(existing code does not return all macs)

after patch:
$time bridge fdb show | wc -l
35085

real    0m2.017s
user    0m0.113s
sys 0m1.942s

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Wilson Kok <wkok@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-01 16:56:15 -07:00
..
datagram.c udp: enable MSG_PEEK at non-zero offset 2016-04-05 16:29:37 -04:00
dev_addr_lists.c
dev_ioctl.c
dev.c net: batch calls to flush_all_backlogs() 2016-08-30 22:17:20 -07:00
devlink.c devlink: add hardware messages tracing facility 2016-07-12 14:20:18 -07:00
drop_monitor.c drop_monitor: make genl_multicast_group const 2016-09-01 14:09:00 -07:00
dst_cache.c
dst.c
ethtool.c sctp: Add GSO support 2016-06-03 19:37:21 -04:00
fib_rules.c fib_rules: Added NLM_F_EXCL support to fib_nl_newrule 2016-06-30 08:23:19 -04:00
filter.c bpf: get rid of cgroup helper related ifdefs 2016-08-18 23:38:16 -07:00
flow_dissector.c flow_dissector: Get vlan priority in addition to vlan id 2016-08-18 23:13:13 -07:00
flow.c
gen_estimator.c net: sched: do not acquire qdisc spinlock in qdisc/class stats dump 2016-06-07 16:37:14 -07:00
gen_stats.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-06-10 11:52:24 -07:00
hwbm.c net: hwbm: Fix unbalanced spinlock in error case 2016-05-25 12:35:09 -07:00
link_watch.c
lwtunnel.c net: lwtunnel: Handle fragmentation 2016-08-30 22:27:18 -07:00
Makefile
neighbour.c neigh: allow admin to set NUD_STALE 2016-08-08 15:36:38 -07:00
net_namespace.c netns: make nla_policy const 2016-09-01 14:09:00 -07:00
net-procfs.c net: remove NETDEV_TX_LOCKED support 2016-04-26 15:53:05 -04:00
net-sysfs.c net: introduce NETDEV_CHANGE_TX_QUEUE_LEN 2016-07-01 05:32:17 -04:00
net-sysfs.h
net-traces.c
netclassid_cgroup.c
netevent.c
netpoll.c net: tracepoint napi:napi_poll add work and budget 2016-07-09 18:05:02 -04:00
netprio_cgroup.c
pktgen.c net: pktgen: support injecting packets for qdisc testing 2016-07-04 16:07:34 -07:00
ptp_classifier.c
request_sock.c
rtnetlink.c rtnetlink: fdb dump: optimize by saving last interface markers 2016-09-01 16:56:15 -07:00
scm.c
secure_seq.c
skbuff.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-06 10:35:22 -07:00
sock_diag.c sock_diag: align nlattr properly when needed 2016-04-26 12:00:48 -04:00
sock_reuseport.c
sock.c net: remove clear_sk() method 2016-08-23 23:25:29 -07:00
stream.c
sysctl_net_core.c bpf: add generic constant blinding for use in jits 2016-05-16 13:49:32 -04:00
timestamping.c
tso.c
utils.c net: the space is required before the open parenthesis '(' 2016-06-29 05:15:14 -04:00