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ipv6: Fix soft lockups in fib6_select_path under high next hop churn
Soft lockups have been observed on a cluster of Linux-based edge routers
located in a highly dynamic environment. Using the `bird` service, these
routers continuously update BGP-advertised routes due to frequently
changing nexthop destinations, while also managing significant IPv6
traffic. The lockups occur during the traversal of the multipath
circular linked-list in the `fib6_select_path` function, particularly
while iterating through the siblings in the list. The issue typically
arises when the nodes of the linked list are unexpectedly deleted
concurrently on a different core—indicated by their 'next' and
'previous' elements pointing back to the node itself and their reference
count dropping to zero. This results in an infinite loop, leading to a
soft lockup that triggers a system panic via the watchdog timer.
Apply RCU primitives in the problematic code sections to resolve the
issue. Where necessary, update the references to fib6_siblings to
annotate or use the RCU APIs.
Include a test script that reproduces the issue. The script
periodically updates the routing table while generating a heavy load
of outgoing IPv6 traffic through multiple iperf3 clients. It
consistently induces infinite soft lockups within a couple of minutes.
Kernel log:
0 [ffffbd13003e8d30] machine_kexec at ffffffff8ceaf3eb
1 [ffffbd13003e8d90] __crash_kexec at ffffffff8d0120e3
2 [ffffbd13003e8e58] panic at ffffffff8cef65d4
3 [ffffbd13003e8ed8] watchdog_timer_fn at ffffffff8d05cb03
4 [ffffbd13003e8f08] __hrtimer_run_queues at ffffffff8cfec62f
5 [ffffbd13003e8f70] hrtimer_interrupt at ffffffff8cfed756
6 [ffffbd13003e8fd0] __sysvec_apic_timer_interrupt at ffffffff8cea01af
7 [ffffbd13003e8ff0] sysvec_apic_timer_interrupt at ffffffff8df1b83d
-- <IRQ stack> --
8 [ffffbd13003d3708] asm_sysvec_apic_timer_interrupt at ffffffff8e000ecb
[exception RIP: fib6_select_path+299]
RIP: ffffffff8ddafe7b RSP: ffffbd13003d37b8 RFLAGS: 00000287
RAX: ffff975850b43600 RBX: ffff975850b40200 RCX: 0000000000000000
RDX: 000000003fffffff RSI: 0000000051d383e4 RDI: ffff975850b43618
RBP: ffffbd13003d3800 R8: 0000000000000000 R9: ffff975850b40200
R10: 0000000000000000 R11: 0000000000000000 R12: ffffbd13003d3830
R13: ffff975850b436a8 R14: ffff975850b43600 R15: 0000000000000007
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
9 [ffffbd13003d3808] ip6_pol_route at ffffffff8ddb030c
10 [ffffbd13003d3888] ip6_pol_route_input at ffffffff8ddb068c
11 [ffffbd13003d3898] fib6_rule_lookup at ffffffff8ddf02b5
12 [ffffbd13003d3928] ip6_route_input at ffffffff8ddb0f47
13 [ffffbd13003d3a18] ip6_rcv_finish_core.constprop.0 at ffffffff8dd950d0
14 [ffffbd13003d3a30] ip6_list_rcv_finish.constprop.0 at ffffffff8dd96274
15 [ffffbd13003d3a98] ip6_sublist_rcv at ffffffff8dd96474
16 [ffffbd13003d3af8] ipv6_list_rcv at ffffffff8dd96615
17 [ffffbd13003d3b60] __netif_receive_skb_list_core at ffffffff8dc16fec
18 [ffffbd13003d3be0] netif_receive_skb_list_internal at ffffffff8dc176b3
19 [ffffbd13003d3c50] napi_gro_receive at ffffffff8dc565b9
20 [ffffbd13003d3c80] ice_receive_skb at ffffffffc087e4f5 [ice]
21 [ffffbd13003d3c90] ice_clean_rx_irq at ffffffffc0881b80 [ice]
22 [ffffbd13003d3d20] ice_napi_poll at ffffffffc088232f [ice]
23 [ffffbd13003d3d80] __napi_poll at ffffffff8dc18000
24 [ffffbd13003d3db8] net_rx_action at ffffffff8dc18581
25 [ffffbd13003d3e40] __do_softirq at ffffffff8df352e9
26 [ffffbd13003d3eb0] run_ksoftirqd at ffffffff8ceffe47
27 [ffffbd13003d3ec0] smpboot_thread_fn at ffffffff8cf36a30
28 [ffffbd13003d3ee8] kthread at ffffffff8cf2b39f
29 [ffffbd13003d3f28] ret_from_fork at ffffffff8ce5fa64
30 [ffffbd13003d3f50] ret_from_fork_asm at ffffffff8ce03cbb
Fixes: 66f5d6ce53 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Reported-by: Adrian Oliver <kernel@aoliver.ca>
Signed-off-by: Omid Ehtemam-Haghighi <omid.ehtemamhaghighi@menlosecurity.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ido Schimmel <idosch@idosch.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Simon Horman <horms@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20241106010236.1239299-1-omid.ehtemamhaghighi@menlosecurity.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Omid Ehtemam-Haghighi
Jakub Kicinski
parent
c4e39b895a
commit
d9ccb18f83
@ -1183,8 +1183,8 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
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while (sibling) {
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if (sibling->fib6_metric == rt->fib6_metric &&
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rt6_qualify_for_ecmp(sibling)) {
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list_add_tail(&rt->fib6_siblings,
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&sibling->fib6_siblings);
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list_add_tail_rcu(&rt->fib6_siblings,
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&sibling->fib6_siblings);
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break;
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}
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sibling = rcu_dereference_protected(sibling->fib6_next,
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@ -1245,7 +1245,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
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fib6_siblings)
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sibling->fib6_nsiblings--;
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rt->fib6_nsiblings = 0;
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list_del_init(&rt->fib6_siblings);
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list_del_rcu(&rt->fib6_siblings);
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rt6_multipath_rebalance(next_sibling);
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return err;
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}
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@ -1963,7 +1963,7 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
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&rt->fib6_siblings, fib6_siblings)
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sibling->fib6_nsiblings--;
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rt->fib6_nsiblings = 0;
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list_del_init(&rt->fib6_siblings);
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list_del_rcu(&rt->fib6_siblings);
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rt6_multipath_rebalance(next_sibling);
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}
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@ -416,8 +416,8 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
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struct flowi6 *fl6, int oif, bool have_oif_match,
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const struct sk_buff *skb, int strict)
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{
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struct fib6_info *sibling, *next_sibling;
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struct fib6_info *match = res->f6i;
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struct fib6_info *sibling;
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if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
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goto out;
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@ -443,8 +443,8 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
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if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
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goto out;
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list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
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fib6_siblings) {
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list_for_each_entry_rcu(sibling, &match->fib6_siblings,
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fib6_siblings) {
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const struct fib6_nh *nh = sibling->fib6_nh;
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int nh_upper_bound;
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@ -5195,14 +5195,18 @@ static void ip6_route_mpath_notify(struct fib6_info *rt,
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* nexthop. Since sibling routes are always added at the end of
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* the list, find the first sibling of the last route appended
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*/
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rcu_read_lock();
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if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
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rt = list_first_entry(&rt_last->fib6_siblings,
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struct fib6_info,
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fib6_siblings);
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rt = list_first_or_null_rcu(&rt_last->fib6_siblings,
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struct fib6_info,
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fib6_siblings);
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}
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if (rt)
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inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
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rcu_read_unlock();
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}
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static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
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@ -5547,17 +5551,21 @@ static size_t rt6_nlmsg_size(struct fib6_info *f6i)
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nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
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&nexthop_len);
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} else {
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struct fib6_info *sibling, *next_sibling;
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struct fib6_nh *nh = f6i->fib6_nh;
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struct fib6_info *sibling;
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nexthop_len = 0;
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if (f6i->fib6_nsiblings) {
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rt6_nh_nlmsg_size(nh, &nexthop_len);
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list_for_each_entry_safe(sibling, next_sibling,
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&f6i->fib6_siblings, fib6_siblings) {
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rcu_read_lock();
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list_for_each_entry_rcu(sibling, &f6i->fib6_siblings,
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fib6_siblings) {
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rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
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}
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rcu_read_unlock();
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}
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nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
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}
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@ -5721,7 +5729,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
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lwtunnel_fill_encap(skb, dst->lwtstate, RTA_ENCAP, RTA_ENCAP_TYPE) < 0)
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goto nla_put_failure;
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} else if (rt->fib6_nsiblings) {
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struct fib6_info *sibling, *next_sibling;
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struct fib6_info *sibling;
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struct nlattr *mp;
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mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
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@ -5733,14 +5741,21 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
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0) < 0)
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goto nla_put_failure;
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list_for_each_entry_safe(sibling, next_sibling,
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&rt->fib6_siblings, fib6_siblings) {
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rcu_read_lock();
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list_for_each_entry_rcu(sibling, &rt->fib6_siblings,
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fib6_siblings) {
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if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
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sibling->fib6_nh->fib_nh_weight,
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AF_INET6, 0) < 0)
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AF_INET6, 0) < 0) {
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rcu_read_unlock();
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goto nla_put_failure;
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}
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}
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rcu_read_unlock();
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nla_nest_end(skb, mp);
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} else if (rt->nh) {
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if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
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@ -6177,7 +6192,7 @@ void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
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err = -ENOBUFS;
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seq = info->nlh ? info->nlh->nlmsg_seq : 0;
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skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
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skb = nlmsg_new(rt6_nlmsg_size(rt), GFP_ATOMIC);
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if (!skb)
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goto errout;
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@ -6190,7 +6205,7 @@ void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
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goto errout;
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}
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rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
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info->nlh, gfp_any());
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info->nlh, GFP_ATOMIC);
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return;
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errout:
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rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
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@ -96,6 +96,7 @@ TEST_PROGS += fdb_flush.sh
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TEST_PROGS += fq_band_pktlimit.sh
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TEST_PROGS += vlan_hw_filter.sh
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TEST_PROGS += bpf_offload.py
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TEST_PROGS += ipv6_route_update_soft_lockup.sh
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# YNL files, must be before "include ..lib.mk"
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YNL_GEN_FILES := ncdevmem
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262
tools/testing/selftests/net/ipv6_route_update_soft_lockup.sh
Executable file
262
tools/testing/selftests/net/ipv6_route_update_soft_lockup.sh
Executable file
@ -0,0 +1,262 @@
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#!/bin/bash
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# SPDX-License-Identifier: GPL-2.0
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#
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# Testing for potential kernel soft lockup during IPv6 routing table
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# refresh under heavy outgoing IPv6 traffic. If a kernel soft lockup
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# occurs, a kernel panic will be triggered to prevent associated issues.
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#
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#
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# Test Environment Layout
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#
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# ┌----------------┐ ┌----------------┐
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# | SOURCE_NS | | SINK_NS |
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# | NAMESPACE | | NAMESPACE |
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# |(iperf3 clients)| |(iperf3 servers)|
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# | | | |
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# | | | |
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# | ┌-----------| nexthops |---------┐ |
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# | |veth_source|<--------------------------------------->|veth_sink|<┐ |
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# | └-----------|2001:0DB8:1::0:1/96 2001:0DB8:1::1:1/96 |---------┘ | |
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# | | ^ 2001:0DB8:1::1:2/96 | | |
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# | | . . | fwd | |
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# | ┌---------┐ | . . | | |
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# | | IPv6 | | . . | V |
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# | | routing | | . 2001:0DB8:1::1:80/96| ┌-----┐ |
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# | | table | | . | | lo | |
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# | | nexthop | | . └--------┴-----┴-┘
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# | | update | | ............................> 2001:0DB8:2::1:1/128
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# | └-------- ┘ |
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# └----------------┘
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#
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# The test script sets up two network namespaces, source_ns and sink_ns,
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# connected via a veth link. Within source_ns, it continuously updates the
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# IPv6 routing table by flushing and inserting IPV6_NEXTHOP_ADDR_COUNT nexthop
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# IPs destined for SINK_LOOPBACK_IP_ADDR in sink_ns. This refresh occurs at a
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# rate of 1/ROUTING_TABLE_REFRESH_PERIOD per second for TEST_DURATION seconds.
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#
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# Simultaneously, multiple iperf3 clients within source_ns generate heavy
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# outgoing IPv6 traffic. Each client is assigned a unique port number starting
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# at 5000 and incrementing sequentially. Each client targets a unique iperf3
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# server running in sink_ns, connected to the SINK_LOOPBACK_IFACE interface
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# using the same port number.
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#
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# The number of iperf3 servers and clients is set to half of the total
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# available cores on each machine.
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#
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# NOTE: We have tested this script on machines with various CPU specifications,
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# ranging from lower to higher performance as listed below. The test script
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# effectively triggered a kernel soft lockup on machines running an unpatched
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# kernel in under a minute:
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#
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# - 1x Intel Xeon E-2278G 8-Core Processor @ 3.40GHz
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# - 1x Intel Xeon E-2378G Processor 8-Core @ 2.80GHz
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# - 1x AMD EPYC 7401P 24-Core Processor @ 2.00GHz
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# - 1x AMD EPYC 7402P 24-Core Processor @ 2.80GHz
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# - 2x Intel Xeon Gold 5120 14-Core Processor @ 2.20GHz
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# - 1x Ampere Altra Q80-30 80-Core Processor @ 3.00GHz
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# - 2x Intel Xeon Gold 5120 14-Core Processor @ 2.20GHz
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# - 2x Intel Xeon Silver 4214 24-Core Processor @ 2.20GHz
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# - 1x AMD EPYC 7502P 32-Core @ 2.50GHz
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# - 1x Intel Xeon Gold 6314U 32-Core Processor @ 2.30GHz
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# - 2x Intel Xeon Gold 6338 32-Core Processor @ 2.00GHz
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#
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# On less performant machines, you may need to increase the TEST_DURATION
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# parameter to enhance the likelihood of encountering a race condition leading
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# to a kernel soft lockup and avoid a false negative result.
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#
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# NOTE: The test may not produce the expected result in virtualized
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# environments (e.g., qemu) due to differences in timing and CPU handling,
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# which can affect the conditions needed to trigger a soft lockup.
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source lib.sh
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source net_helper.sh
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TEST_DURATION=300
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ROUTING_TABLE_REFRESH_PERIOD=0.01
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IPERF3_BITRATE="300m"
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IPV6_NEXTHOP_ADDR_COUNT="128"
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IPV6_NEXTHOP_ADDR_MASK="96"
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IPV6_NEXTHOP_PREFIX="2001:0DB8:1"
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SOURCE_TEST_IFACE="veth_source"
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SOURCE_TEST_IP_ADDR="2001:0DB8:1::0:1/96"
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SINK_TEST_IFACE="veth_sink"
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# ${SINK_TEST_IFACE} is populated with the following range of IPv6 addresses:
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# 2001:0DB8:1::1:1 to 2001:0DB8:1::1:${IPV6_NEXTHOP_ADDR_COUNT}
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SINK_LOOPBACK_IFACE="lo"
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SINK_LOOPBACK_IP_MASK="128"
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SINK_LOOPBACK_IP_ADDR="2001:0DB8:2::1:1"
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nexthop_ip_list=""
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termination_signal=""
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kernel_softlokup_panic_prev_val=""
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terminate_ns_processes_by_pattern() {
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local ns=$1
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local pattern=$2
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for pid in $(ip netns pids ${ns}); do
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[ -e /proc/$pid/cmdline ] && grep -qe "${pattern}" /proc/$pid/cmdline && kill -9 $pid
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done
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}
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cleanup() {
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echo "info: cleaning up namespaces and terminating all processes within them..."
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# Terminate iperf3 instances running in the source_ns. To avoid race
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# conditions, first iterate over the PIDs and terminate those
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# associated with the bash shells running the
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# `while true; do iperf3 -c ...; done` loops. In a second iteration,
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# terminate the individual `iperf3 -c ...` instances.
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terminate_ns_processes_by_pattern ${source_ns} while
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terminate_ns_processes_by_pattern ${source_ns} iperf3
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# Repeat the same process for sink_ns
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terminate_ns_processes_by_pattern ${sink_ns} while
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terminate_ns_processes_by_pattern ${sink_ns} iperf3
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# Check if any iperf3 instances are still running. This could happen
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# if a core has entered an infinite loop and the timeout for detecting
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# the soft lockup has not expired, but either the test interval has
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# already elapsed or the test was terminated manually (e.g., with ^C)
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for pid in $(ip netns pids ${source_ns}); do
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if [ -e /proc/$pid/cmdline ] && grep -qe 'iperf3' /proc/$pid/cmdline; then
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echo "FAIL: unable to terminate some iperf3 instances. Soft lockup is underway. A kernel panic is on the way!"
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exit ${ksft_fail}
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fi
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done
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if [ "$termination_signal" == "SIGINT" ]; then
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echo "SKIP: Termination due to ^C (SIGINT)"
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elif [ "$termination_signal" == "SIGALRM" ]; then
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echo "PASS: No kernel soft lockup occurred during this ${TEST_DURATION} second test"
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fi
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cleanup_ns ${source_ns} ${sink_ns}
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|
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sysctl -qw kernel.softlockup_panic=${kernel_softlokup_panic_prev_val}
|
||||
}
|
||||
|
||||
setup_prepare() {
|
||||
setup_ns source_ns sink_ns
|
||||
|
||||
ip -n ${source_ns} link add name ${SOURCE_TEST_IFACE} type veth peer name ${SINK_TEST_IFACE} netns ${sink_ns}
|
||||
|
||||
# Setting up the Source namespace
|
||||
ip -n ${source_ns} addr add ${SOURCE_TEST_IP_ADDR} dev ${SOURCE_TEST_IFACE}
|
||||
ip -n ${source_ns} link set dev ${SOURCE_TEST_IFACE} qlen 10000
|
||||
ip -n ${source_ns} link set dev ${SOURCE_TEST_IFACE} up
|
||||
ip netns exec ${source_ns} sysctl -qw net.ipv6.fib_multipath_hash_policy=1
|
||||
|
||||
# Setting up the Sink namespace
|
||||
ip -n ${sink_ns} addr add ${SINK_LOOPBACK_IP_ADDR}/${SINK_LOOPBACK_IP_MASK} dev ${SINK_LOOPBACK_IFACE}
|
||||
ip -n ${sink_ns} link set dev ${SINK_LOOPBACK_IFACE} up
|
||||
ip netns exec ${sink_ns} sysctl -qw net.ipv6.conf.${SINK_LOOPBACK_IFACE}.forwarding=1
|
||||
|
||||
ip -n ${sink_ns} link set ${SINK_TEST_IFACE} up
|
||||
ip netns exec ${sink_ns} sysctl -qw net.ipv6.conf.${SINK_TEST_IFACE}.forwarding=1
|
||||
|
||||
|
||||
# Populate nexthop IPv6 addresses on the test interface in the sink_ns
|
||||
echo "info: populating ${IPV6_NEXTHOP_ADDR_COUNT} IPv6 addresses on the ${SINK_TEST_IFACE} interface ..."
|
||||
for IP in $(seq 1 ${IPV6_NEXTHOP_ADDR_COUNT}); do
|
||||
ip -n ${sink_ns} addr add ${IPV6_NEXTHOP_PREFIX}::$(printf "1:%x" "${IP}")/${IPV6_NEXTHOP_ADDR_MASK} dev ${SINK_TEST_IFACE};
|
||||
done
|
||||
|
||||
# Preparing list of nexthops
|
||||
for IP in $(seq 1 ${IPV6_NEXTHOP_ADDR_COUNT}); do
|
||||
nexthop_ip_list=$nexthop_ip_list" nexthop via ${IPV6_NEXTHOP_PREFIX}::$(printf "1:%x" $IP) dev ${SOURCE_TEST_IFACE} weight 1"
|
||||
done
|
||||
}
|
||||
|
||||
|
||||
test_soft_lockup_during_routing_table_refresh() {
|
||||
# Start num_of_iperf_servers iperf3 servers in the sink_ns namespace,
|
||||
# each listening on ports starting at 5001 and incrementing
|
||||
# sequentially. Since iperf3 instances may terminate unexpectedly, a
|
||||
# while loop is used to automatically restart them in such cases.
|
||||
echo "info: starting ${num_of_iperf_servers} iperf3 servers in the sink_ns namespace ..."
|
||||
for i in $(seq 1 ${num_of_iperf_servers}); do
|
||||
cmd="iperf3 --bind ${SINK_LOOPBACK_IP_ADDR} -s -p $(printf '5%03d' ${i}) --rcv-timeout 200 &>/dev/null"
|
||||
ip netns exec ${sink_ns} bash -c "while true; do ${cmd}; done &" &>/dev/null
|
||||
done
|
||||
|
||||
# Wait for the iperf3 servers to be ready
|
||||
for i in $(seq ${num_of_iperf_servers}); do
|
||||
port=$(printf '5%03d' ${i});
|
||||
wait_local_port_listen ${sink_ns} ${port} tcp
|
||||
done
|
||||
|
||||
# Continuously refresh the routing table in the background within
|
||||
# the source_ns namespace
|
||||
ip netns exec ${source_ns} bash -c "
|
||||
while \$(ip netns list | grep -q ${source_ns}); do
|
||||
ip -6 route add ${SINK_LOOPBACK_IP_ADDR}/${SINK_LOOPBACK_IP_MASK} ${nexthop_ip_list};
|
||||
sleep ${ROUTING_TABLE_REFRESH_PERIOD};
|
||||
ip -6 route delete ${SINK_LOOPBACK_IP_ADDR}/${SINK_LOOPBACK_IP_MASK};
|
||||
done &"
|
||||
|
||||
# Start num_of_iperf_servers iperf3 clients in the source_ns namespace,
|
||||
# each sending TCP traffic on sequential ports starting at 5001.
|
||||
# Since iperf3 instances may terminate unexpectedly (e.g., if the route
|
||||
# to the server is deleted in the background during a route refresh), a
|
||||
# while loop is used to automatically restart them in such cases.
|
||||
echo "info: starting ${num_of_iperf_servers} iperf3 clients in the source_ns namespace ..."
|
||||
for i in $(seq 1 ${num_of_iperf_servers}); do
|
||||
cmd="iperf3 -c ${SINK_LOOPBACK_IP_ADDR} -p $(printf '5%03d' ${i}) --length 64 --bitrate ${IPERF3_BITRATE} -t 0 --connect-timeout 150 &>/dev/null"
|
||||
ip netns exec ${source_ns} bash -c "while true; do ${cmd}; done &" &>/dev/null
|
||||
done
|
||||
|
||||
echo "info: IPv6 routing table is being updated at the rate of $(echo "1/${ROUTING_TABLE_REFRESH_PERIOD}" | bc)/s for ${TEST_DURATION} seconds ..."
|
||||
echo "info: A kernel soft lockup, if detected, results in a kernel panic!"
|
||||
|
||||
wait
|
||||
}
|
||||
|
||||
# Make sure 'iperf3' is installed, skip the test otherwise
|
||||
if [ ! -x "$(command -v "iperf3")" ]; then
|
||||
echo "SKIP: 'iperf3' is not installed. Skipping the test."
|
||||
exit ${ksft_skip}
|
||||
fi
|
||||
|
||||
# Determine the number of cores on the machine
|
||||
num_of_iperf_servers=$(( $(nproc)/2 ))
|
||||
|
||||
# Check if we are running on a multi-core machine, skip the test otherwise
|
||||
if [ "${num_of_iperf_servers}" -eq 0 ]; then
|
||||
echo "SKIP: This test is not valid on a single core machine!"
|
||||
exit ${ksft_skip}
|
||||
fi
|
||||
|
||||
# Since the kernel soft lockup we're testing causes at least one core to enter
|
||||
# an infinite loop, destabilizing the host and likely affecting subsequent
|
||||
# tests, we trigger a kernel panic instead of reporting a failure and
|
||||
# continuing
|
||||
kernel_softlokup_panic_prev_val=$(sysctl -n kernel.softlockup_panic)
|
||||
sysctl -qw kernel.softlockup_panic=1
|
||||
|
||||
handle_sigint() {
|
||||
termination_signal="SIGINT"
|
||||
cleanup
|
||||
exit ${ksft_skip}
|
||||
}
|
||||
|
||||
handle_sigalrm() {
|
||||
termination_signal="SIGALRM"
|
||||
cleanup
|
||||
exit ${ksft_pass}
|
||||
}
|
||||
|
||||
trap handle_sigint SIGINT
|
||||
trap handle_sigalrm SIGALRM
|
||||
|
||||
(sleep ${TEST_DURATION} && kill -s SIGALRM $$)&
|
||||
|
||||
setup_prepare
|
||||
test_soft_lockup_during_routing_table_refresh
|
||||
Loading…
Reference in New Issue
Block a user