Messages in this thread | | | Date | Tue, 3 Jan 2012 14:35:05 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH block/for-3.3/core] block: an exiting task should be allowed to create io_context |
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On Tue, Jan 03, 2012 at 02:13:01PM -0800, Tejun Heo wrote: > > That's pretty odd. Given Hughs report as well, it sure does sound like > > we now have some life time issues with cfqq's. > > Hmmm... I disabled cfqq merge logic (commented out > cfq_close_cooperator() and the following cfq_setup_merge() calls) in > cfq_select_queue() and neither is triggering for quite a while now. > Maybe cfqq refcnt is getting borked over cfqq merging / splitting? It > would also explain the low frequency of the issue too. I'll try to > further isolate it but It would be awesome if someone more familiar > with the logic can go over that part.
Scrap that. It triggered and yeah cfq_get_next_queue() is retrieving empty cfqq from the service tree.
Thanks.
-- tejun
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