swh:1:snp:3c665ee4f67729f27f2e40193ab88e7298cf0fef
Revision 7433819a1eefd4e74711fffd6d54e30a644ef240 authored by Eric Dumazet on 31 May 2012, 21:00:26 UTC, committed by David S. Miller on 01 June 2012, 18:22:11 UTC
Another problem on SYNFLOOD/DDOS attack is the inetpeer cache getting larger and larger, using lots of memory and cpu time. tcp_v4_send_synack() ->inet_csk_route_req() ->ip_route_output_flow() ->rt_set_nexthop() ->rt_init_metrics() ->inet_getpeer( create = true) This is a side effect of commit a4daad6b09230 (net: Pre-COW metrics for TCP) added in 2.6.39 Possible solution : Instruct inet_csk_route_req() to remove FLOWI_FLAG_PRECOW_METRICS Before patch : # grep peer /proc/slabinfo inet_peer_cache 4175430 4175430 192 42 2 : tunables 0 0 0 : slabdata 99415 99415 0 Samples: 41K of event 'cycles', Event count (approx.): 30716565122 + 20,24% ksoftirqd/0 [kernel.kallsyms] [k] inet_getpeer + 8,19% ksoftirqd/0 [kernel.kallsyms] [k] peer_avl_rebalance.isra.1 + 4,81% ksoftirqd/0 [kernel.kallsyms] [k] sha_transform + 3,64% ksoftirqd/0 [kernel.kallsyms] [k] fib_table_lookup + 2,36% ksoftirqd/0 [ixgbe] [k] ixgbe_poll + 2,16% ksoftirqd/0 [kernel.kallsyms] [k] __ip_route_output_key + 2,11% ksoftirqd/0 [kernel.kallsyms] [k] kernel_map_pages + 2,11% ksoftirqd/0 [kernel.kallsyms] [k] ip_route_input_common + 2,01% ksoftirqd/0 [kernel.kallsyms] [k] __inet_lookup_established + 1,83% ksoftirqd/0 [kernel.kallsyms] [k] md5_transform + 1,75% ksoftirqd/0 [kernel.kallsyms] [k] check_leaf.isra.9 + 1,49% ksoftirqd/0 [kernel.kallsyms] [k] ipt_do_table + 1,46% ksoftirqd/0 [kernel.kallsyms] [k] hrtimer_interrupt + 1,45% ksoftirqd/0 [kernel.kallsyms] [k] kmem_cache_alloc + 1,29% ksoftirqd/0 [kernel.kallsyms] [k] inet_csk_search_req + 1,29% ksoftirqd/0 [kernel.kallsyms] [k] __netif_receive_skb + 1,16% ksoftirqd/0 [kernel.kallsyms] [k] copy_user_generic_string + 1,15% ksoftirqd/0 [kernel.kallsyms] [k] kmem_cache_free + 1,02% ksoftirqd/0 [kernel.kallsyms] [k] tcp_make_synack + 0,93% ksoftirqd/0 [kernel.kallsyms] [k] _raw_spin_lock_bh + 0,87% ksoftirqd/0 [kernel.kallsyms] [k] __call_rcu + 0,84% ksoftirqd/0 [kernel.kallsyms] [k] rt_garbage_collect + 0,84% ksoftirqd/0 [kernel.kallsyms] [k] fib_rules_lookup Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Hans Schillstrom <hans.schillstrom@ericsson.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 0bc777b
Tip revision: 64222515138e43da1fcf288f0289ef1020427b87 authored by Linus Torvalds on 22 October 2021, 05:06:08 UTC
Merge tag 'drm-fixes-2021-10-22' of git://anongit.freedesktop.org/drm/drm
Merge tag 'drm-fixes-2021-10-22' of git://anongit.freedesktop.org/drm/drm
Tip revision: 6422251
File | Mode | Size |
---|---|---|
Documentation | ||
arch | ||
block | ||
crypto | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.gitignore | -rw-r--r-- | 1014 bytes |
.mailmap | -rw-r--r-- | 4.2 KB |
COPYING | -rw-r--r-- | 18.3 KB |
CREDITS | -rw-r--r-- | 92.7 KB |
Kbuild | -rw-r--r-- | 2.5 KB |
Kconfig | -rw-r--r-- | 252 bytes |
MAINTAINERS | -rw-r--r-- | 207.3 KB |
Makefile | -rw-r--r-- | 46.0 KB |
README | -rw-r--r-- | 17.3 KB |
REPORTING-BUGS | -rw-r--r-- | 3.3 KB |
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...