Hello,
debugged on next occurence. Here is info on stucked revalidator525:
Id Target Id Frame
* 1 Thread 0x7fde892b4e00 (LWP 1499) "ovs-vswitchd"
0x00007fde879f9bf9 in __GI___poll (fds=0x55a40e6d75e0, nfds=2,
timeout=76638) at ../sysdeps/unix/sysv/linux/poll.c:29
2 Thread 0x7fde855a1700 (LWP 2131) "urcu4" 0x00007fde879f9bf9 in
__GI___poll (fds=0x7fde40004d10, nfds=2, timeout=75817) at
../sysdeps/unix/sysv/linux/poll.c:29
3 Thread 0x7fddd1ffb700 (LWP 4596) "handler482" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddb86440e0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
4 Thread 0x7fddd27fc700 (LWP 4597) "handler483" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddd84e11e0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
5 Thread 0x7fddd2ffd700 (LWP 4598) "handler484" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddec3062d0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
6 Thread 0x7fddd37fe700 (LWP 4599) "handler485" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde341c3f80, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
7 Thread 0x7fde86da4700 (LWP 4600) "handler486" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde500e8530, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
8 Thread 0x7fde865a3700 (LWP 4601) "handler487" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddf40c00c0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
9 Thread 0x7fde85da2700 (LWP 4602) "handler488" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddfc06e480, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
10 Thread 0x7fde84da0700 (LWP 4603) "handler489" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde78049250, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
11 Thread 0x7fde73fff700 (LWP 4604) "handler490" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddc8016700, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
12 Thread 0x7fde737fe700 (LWP 4605) "handler491" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fdde800cbd0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
13 Thread 0x7fde72ffd700 (LWP 4606) "handler492" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde60012fb0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
14 Thread 0x7fde727fc700 (LWP 4607) "handler493" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde24017bb0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
15 Thread 0x7fde71ffb700 (LWP 4608) "handler494" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddd40060b0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
16 Thread 0x7fde717fa700 (LWP 4609) "handler495" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde54004ef0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
17 Thread 0x7fde70ff9700 (LWP 4610) "handler496" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde38008630, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
18 Thread 0x7fde5bfff700 (LWP 4611) "handler497" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fdda400c650, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
19 Thread 0x7fde5b7fe700 (LWP 4612) "handler498" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde14015730, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
20 Thread 0x7fde5affd700 (LWP 4614) "handler499" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde28016fc0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
21 Thread 0x7fde5a7fc700 (LWP 4615) "handler500" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddf0007570, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
22 Thread 0x7fde59ffb700 (LWP 4616) "handler501" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde04012990, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
23 Thread 0x7fde597fa700 (LWP 4617) "handler502" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddc0019910, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
24 Thread 0x7fde58ff9700 (LWP 4618) "handler503" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde3c005810, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
25 Thread 0x7fde4bfff700 (LWP 4619) "handler504" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde08005770, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
26 Thread 0x7fde4b7fe700 (LWP 4620) "handler505" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde2c0043e0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
27 Thread 0x7fde4affd700 (LWP 4621) "handler506" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde7c01c4f0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
28 Thread 0x7fde4a7fc700 (LWP 4622) "handler507" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddcc014890, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
29 Thread 0x7fde49ffb700 (LWP 4623) "handler508" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fdda8004c00, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
30 Thread 0x7fde497fa700 (LWP 4624) "handler509" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde0c006450, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
31 Thread 0x7fde48ff9700 (LWP 4625) "handler510" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde64004c40, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
32 Thread 0x7fde13fff700 (LWP 4626) "handler511" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde6c000b20, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
33 Thread 0x7fde137fe700 (LWP 4627) "handler512" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fddc400b240, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
34 Thread 0x7fde12ffd700 (LWP 4628) "handler513" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde180056c0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
35 Thread 0x7fde127fc700 (LWP 4629) "handler514" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fdde0005ea0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
36 Thread 0x7fde11ffb700 (LWP 4630) "handler515" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde00007af0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
37 Thread 0x7fde117fa700 (LWP 4631) "handler516" 0x00007fde879f9bf9
in __GI___poll (fds=0x7fde6800b2d0, nfds=3, timeout=2147483647) at
../sysdeps/unix/sysv/linux/poll.c:29
38 Thread 0x7fde10ff9700 (LWP 4632) "revalidator517"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fde5c0a0960, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
39 Thread 0x7fddfbfff700 (LWP 4633) "revalidator518"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fde4c00bbc0, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
40 Thread 0x7fddfb7fe700 (LWP 4634) "revalidator519"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fddb0036600, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
41 Thread 0x7fddfaffd700 (LWP 4635) "revalidator520"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fdddc06fef0, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
42 Thread 0x7fddfa7fc700 (LWP 4636) "revalidator521"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fde800016a0, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
43 Thread 0x7fddf9ffb700 (LWP 4637) "revalidator522"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fddac07a390, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
44 Thread 0x7fddf97fa700 (LWP 4638) "revalidator523"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fde40043230, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
45 Thread 0x7fddf8ff9700 (LWP 4639) "revalidator524"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fdde4060d20, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
46 Thread 0x7fddd3fff700 (LWP 4640) "revalidator525"
0x00007fde8853237b in futex_abstimed_wait (private=<optimized out>,
abstime=0x0, expected=10, futex_word=0x55a40e4afa78)
at ../sysdeps/unix/sysv/linux/futex-internal.h:172
47 Thread 0x7fddd17fa700 (LWP 4641) "revalidator526"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fde2004bd10, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
48 Thread 0x7fddd0ff9700 (LWP 4642) "revalidator527"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fddbc07be70, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
49 Thread 0x7fddb7fff700 (LWP 4643) "revalidator528"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fde1c04bd20, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
50 Thread 0x7fddb77fe700 (LWP 4644) "revalidator529"
0x00007fde879f9bf9 in __GI___poll (fds=0x7fde30027a50, nfds=2,
timeout=2147483647) at ../sysdeps/unix/sysv/linux/poll.c:29
So here is the thread:
46 Thread 0x7fddd3fff700 (LWP 4640) "revalidator525"
0x00007fde8853237b in futex_abstimed_wait (private=<optimized out>,
abstime=0x0, expected=10, futex_word=0x55a40e4afa78)
at ../sysdeps/unix/sysv/linux/futex-internal.h:172
Any ideas what to do next ?
Thanks
Zdenek
On 14. 10. 19 20:15, Ben Pfaff wrote:
> On Mon, Oct 14, 2019 at 10:11:35AM +0200, Zdenek Janda wrote:
>> Hello,
>> we have really strange issue. Ovs-vswitchd get stucked on ovs_rcu
>> revalidator quiesce, reporting following to the log:
>>
>> 2019-10-14T05:11:18.049Z|00416|ovs_rcu|WARN|blocked 1000 ms waiting for
>> revalidator518 to quiesce
>> 2019-10-14T05:11:19.049Z|00417|ovs_rcu|WARN|blocked 2000 ms waiting for
>> revalidator518 to quiesce
>> 2019-10-14T05:11:21.049Z|00418|ovs_rcu|WARN|blocked 4000 ms waiting for
> ...
>> We have tried to debug this issue, and noticed while running strace or
>> producing core dump will magically unstuck ovs-vswitchd and it starts
>> working immediatelly:
>>
>> gcore `pidof ovs-vswitchd`
>
> The key question is, what is revalidator518 doing when it is failed to
> quiesce? If you attach with GDB and obtain a backtrace from the stuck
> thread (and possibly from the other threads), it would probably provide
> a clue.
>
> Do you have any idea about how busy OVS is when this happens? The
> revalidator threads should not take multiple seconds to do their work,
> but if it happens anyway, it would probably happen when OVS was very
> busy.
>
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