Thanks so much John! I am looking forward to seeing your final test results.
Thanks, Ying On 03/10/2017 05:11 AM, John Thompson wrote: > Thanks Ying. > I am away for a week and will run some tests next when back. > Regards > John > > On 10/03/2017 3:22 AM, "Ying Xue" <ying....@windriver.com > <mailto:ying....@windriver.com>> wrote: > > commit d094c4d5f5 ("tipc: add subscription refcount to avoid invalid > delete") accidently introduce the following deadlock scenarios: > > CPU1: CPU2: > ---------- ---------------- > tipc_nametbl_publish > spin_lock_bh(&tn->nametbl_lock) > tipc_nametbl_insert_publ > tipc_nameseq_insert_publ > tipc_subscrp_report_overlap > tipc_subscrp_get > tipc_subscrp_send_event > tipc_close_conn > tipc_subscrb_release_cb > tipc_subscrb_delete > tipc_subscrp_put > tipc_subscrp_put > tipc_subscrp_kref_release > tipc_nametbl_unsubscribe > spin_lock_bh(&tn->nametbl_lock) > <<grab nametbl_lock again>> > > CPU1: CPU2: > ---------- ---------------- > tipc_nametbl_stop > spin_lock_bh(&tn->nametbl_lock) > tipc_purge_publications > tipc_nameseq_remove_publ > tipc_subscrp_report_overlap > tipc_subscrp_get > tipc_subscrp_send_event > tipc_close_conn > tipc_subscrb_release_cb > tipc_subscrb_delete > tipc_subscrp_put > tipc_subscrp_put > tipc_subscrp_kref_release > tipc_nametbl_unsubscribe > spin_lock_bh(&tn->nametbl_lock) > <<grab nametbl_lock again>> > > The root cause of two deadlocks is that we have to hold nametbl lock > when subscription is freed in tipc_subscrp_kref_release(). In order to > eliminate the need of taking nametbl lock in > tipc_subscrp_kref_release(), the functions protected by nametbl lock > in tipc_subscrp_kref_release() are moved to other places step by step > in the series. > > Change log: > v2: > As Parth's comments, subscription is still present name table after > it's expired. To fix it, we introduce a workqueue, and when > subscription's timer is expired, the subscription will be pushed to > the workqueue through its work. When the work is scheduled, the > subscription be deleted finally. > > Ying Xue (6): > tipc: advance the time of deleting subscription from > subscriber->subscrp_list > tipc: adjust the policy of holding subscription kref > tipc: adjust policy that sub->timer holds subscription kref > tipc: advance the time of calling tipc_nametbl_unsubscribe > tipc: remove unnecessary increasement of subscription refcount > tipc: delete expired subscription > > net/tipc/name_table.c | 2 ++ > net/tipc/server.h | 2 ++ > net/tipc/subscr.c | 64 > ++++++++++++++++++++++++++++++++++++--------------- > net/tipc/subscr.h | 4 ++++ > 4 files changed, 54 insertions(+), 18 deletions(-) > > -- > 2.7.4 > ------------------------------------------------------------------------------ Announcing the Oxford Dictionaries API! The API offers world-renowned dictionary content that is easy and intuitive to access. Sign up for an account today to start using our lexical data to power your apps and projects. Get started today and enter our developer competition. http://sdm.link/oxford _______________________________________________ tipc-discussion mailing list tipc-discussion@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tipc-discussion
