[dm-devel] [PATCH v7 9/9] block: Avoid deadlocks with bio allocation by stacking drivers

Vivek Goyal vgoyal at redhat.com
Tue Sep 4 19:39:49 UTC 2012


On Tue, Sep 04, 2012 at 03:26:19PM -0400, Mikulas Patocka wrote:

[..]
> BTW. can these new-style timerless plugs introduce deadlocks too? What 
> happens when some bios are indefinitely delayed because their requests are 
> held in a plug and a mempool runs out?

I think they will not deadlock because these on stack bios/requests are
flushed/dispatched when process schedules out. So if a submitter blocks
on a mempool, it will be scheduled out and requests on plug will be 
dispatched.

Thanks
Vivek




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