From: i@eivanov.com (Evgeniy Ivanov)
Subject: [lttng-dev] Deadlock in call_rcu_thread when destroy rculfhash node with nested rculfhash
Date: Wed, 19 Oct 2016 12:56:04 +0300 [thread overview]
Message-ID: <CAO6Ho0ea+Mhdoea4b3EL-J4z2wifHPWohq1ps74LQBU+b0-OOQ@mail.gmail.com> (raw)
Hi,
Each node of top level rculfhash has nested rculfhash. Some thread clears
the top level map and then uses rcu_barrier() to wait until everything is
destroyed (it is done to check leaks). Recently it started to dead lock
sometimes with following stacks:
Thread1:
__poll
cds_lfht_destroy <---- nested map
...
free_Node(rcu_head*) <----- node of top level map
call_rcu_thread
Thread2:
syscall
rcu_barrier_qsbr
destroy_all
main
Did call_rcu_thread dead lock with barrier thread? Or is it some kind of
internal deadlock because of nested maps?
--
Cheers,
Evgeniy
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next reply other threads:[~2016-10-19 9:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-19 9:56 Evgeniy Ivanov [this message]
2016-10-19 10:03 ` Evgeniy Ivanov
2016-10-19 15:03 ` Mathieu Desnoyers
2016-10-21 8:19 ` Evgeniy Ivanov
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