linux/net/core
Jon Maxwell af6d10345c ipv6: remove max_size check inline with ipv4
In ip6_dst_gc() replace:

  if (entries > gc_thresh)

With:

  if (entries > ops->gc_thresh)

Sending Ipv6 packets in a loop via a raw socket triggers an issue where a
route is cloned by ip6_rt_cache_alloc() for each packet sent. This quickly
consumes the Ipv6 max_size threshold which defaults to 4096 resulting in
these warnings:

[1]   99.187805] dst_alloc: 7728 callbacks suppressed
[2] Route cache is full: consider increasing sysctl net.ipv6.route.max_size.
.
.
[300] Route cache is full: consider increasing sysctl net.ipv6.route.max_size.

When this happens the packet is dropped and sendto() gets a network is
unreachable error:

remaining pkt 200557 errno 101
remaining pkt 196462 errno 101
.
.
remaining pkt 126821 errno 101

Implement David Aherns suggestion to remove max_size check seeing that Ipv6
has a GC to manage memory usage. Ipv4 already does not check max_size.

Here are some memory comparisons for Ipv4 vs Ipv6 with the patch:

Test by running 5 instances of a program that sends UDP packets to a raw
socket 5000000 times. Compare Ipv4 and Ipv6 performance with a similar
program.

Ipv4:

Before test:

MemFree:        29427108 kB
Slab:             237612 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        2881   3990    192   42    2 : tunables    0    0    0

During test:

MemFree:        29417608 kB
Slab:             247712 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache       44394  44394    192   42    2 : tunables    0    0    0

After test:

MemFree:        29422308 kB
Slab:             238104 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

Ipv6 with patch:

Errno 101 errors are not observed anymore with the patch.

Before test:

MemFree:        29422308 kB
Slab:             238104 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

During Test:

MemFree:        29431516 kB
Slab:             240940 kB

ip6_dst_cache      11980  12064    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

After Test:

MemFree:        29441816 kB
Slab:             238132 kB

ip6_dst_cache       1902   2432    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

Tested-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230112012532.311021-1-jmaxwell37@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-13 20:59:14 -08:00
..
bpf_sk_storage.c bpf: Fix a compilation failure with clang lto build 2022-11-30 17:13:25 -08:00
datagram.c tcp: TX zerocopy should not sense pfmemalloc status 2022-09-02 12:29:02 +01:00
dev.c net: Fix documentation for unregister_netdevice_notifier_net 2022-12-19 10:42:41 +00:00
dev.h net: add new helper unregister_netdevice_many_notify 2022-10-31 18:10:21 -07:00
dev_addr_lists.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
dev_addr_lists_test.c kunit: Use KUNIT_EXPECT_MEMEQ macro 2022-10-27 02:40:14 -06:00
dev_ioctl.c net: dev: Convert sa_data to flexible array in struct sockaddr 2022-10-25 11:44:20 -07:00
drop_monitor.c genetlink: introduce split op representation 2022-11-07 12:30:16 +00:00
dst.c ipv6: remove max_size check inline with ipv4 2023-01-13 20:59:14 -08:00
dst_cache.c wireguard: device: reset peer src endpoint when netns exits 2021-11-29 19:50:45 -08:00
failover.c net: failover: use IFF_NO_ADDRCONF flag to prevent ipv6 addrconf 2022-12-12 15:18:25 -08:00
fib_notifier.c
fib_rules.c fib: expand fib_rule_policy 2021-12-16 07:18:35 -08:00
filter.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-01-05 15:34:11 -08:00
flow_dissector.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-11-29 13:04:52 -08:00
flow_offload.c net: flow_offload: add support for ARP frame matching 2022-11-14 11:24:16 +00:00
gen_estimator.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
gen_stats.c net: Remove the obsolte u64_stats_fetch_*_irq() users (net). 2022-10-28 20:13:54 -07:00
gro.c gro: take care of DODGY packets 2023-01-09 07:37:07 +00:00
gro_cells.c net: drop the weight argument from netif_napi_add 2022-09-28 18:57:14 -07:00
hwbm.c
link_watch.c net: linkwatch: only report IF_OPER_LOWERLAYERDOWN if iflink is actually down 2022-11-16 09:45:00 +00:00
lwt_bpf.c bpf, lwt: Fix crash when using bpf_skb_set_tunnel_key() from bpf_xmit lwt hook 2022-04-22 17:45:25 +02:00
lwtunnel.c xfrm: lwtunnel: squelch kernel warning in case XFRM encap type is not available 2022-10-12 10:45:51 +02:00
Makefile devlink: move code to a dedicated directory 2023-01-05 22:12:00 -08:00
neighbour.c Random number generator updates for Linux 6.2-rc1. 2022-12-12 16:22:22 -08:00
net-procfs.c net: extract a few internals from netdevice.h 2022-04-07 20:32:09 -07:00
net-sysfs.c Driver Core changes for 6.2-rc1 2022-12-16 03:54:54 -08:00
net-sysfs.h
net-traces.c tcp: add tracepoint for checksum errors 2021-05-14 15:26:03 -07:00
net_namespace.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-10-24 13:44:11 -07:00
netclassid_cgroup.c core: Variable type completion 2022-08-31 09:40:34 +01:00
netevent.c net: core: Correct function name netevent_unregister_notifier() in the kerneldoc 2021-03-28 17:56:56 -07:00
netpoll.c net: move from strlcpy with unused retval to strscpy 2022-08-22 18:06:18 -07:00
netprio_cgroup.c bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode 2021-09-13 16:35:58 -07:00
of_net.c of: net: export of_get_mac_address_nvmem() 2022-11-29 10:45:53 +01:00
page_pool.c - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe 2022-08-05 16:32:45 -07:00
pktgen.c treewide: use get_random_u32_inclusive() when possible 2022-11-18 02:18:02 +01:00
ptp_classifier.c ptp: Add generic PTP is_sync() function 2022-03-07 11:31:34 +00:00
request_sock.c
rtnetlink.c net: expose devlink port over rtnetlink 2022-11-03 20:48:37 -07:00
scm.c memcg: enable accounting for scm_fp_list objects 2021-07-20 06:00:38 -07:00
secure_seq.c tcp: Fix data-races around sysctl knobs related to SYN option. 2022-07-20 10:14:49 +01:00
selftests.c net: core: constify mac addrs in selftests 2021-10-24 13:59:44 +01:00
skbuff.c net: skb: remove old comments about frag_size for build_skb() 2023-01-09 08:15:04 +00:00
skmsg.c bpf, sockmap: Fix missing BPF_F_INGRESS flag when using apply_bytes 2022-12-01 01:07:32 +01:00
sock.c net: Introduce sk_use_task_frag in struct sock. 2022-12-19 17:28:49 -08:00
sock_destructor.h skb_expand_head() adjust skb->truesize incorrectly 2021-10-22 12:35:51 -07:00
sock_diag.c net: fix __sock_gen_cookie() 2022-11-21 20:36:30 -08:00
sock_map.c bpf, sockmap: fix race in sock_map_free() 2022-12-04 18:53:51 -08:00
sock_reuseport.c soreuseport: Fix socket selection for SO_INCOMING_CPU. 2022-10-25 11:35:16 +02:00
stream.c net: stream: purge sk_error_queue in sk_stream_kill_queues() 2022-12-19 12:33:16 +00:00
sysctl_net_core.c sysctl: expose all net/core sysctls inside netns 2023-01-06 12:41:52 +00:00
timestamping.c
tso.c net: tso: inline tso_count_descs() 2022-12-12 15:04:39 -08:00
utils.c net: core: inet[46]_pton strlen len types 2022-11-01 21:14:39 -07:00
xdp.c xdp: improve page_pool xdp_return performance 2022-09-26 11:28:19 -07:00