With cmwq, there's no reason to use dedicated rds_ib_fmr_wq - it's not
in the memory reclaim path and the maximum number of concurrent work
items is bound by the number of devices.  Drop it and use system_wq
instead.  This rds_ib_fmr_init/exit() noops.  Both removed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andy Grover <andy.grover@oracle.com>

The RDS protocol has lots of functions that should be
declared static. rds_message_get/add_version_extension is
removed since it defined but never used.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is basically just a cleanup.  IRQs were disabled on the previous
line so we don't need to do it again here.  In the current code IRQs
would get turned on one line earlier than intended.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The RDS IB device list wasn't protected by any locking.  Traversal in
both the get_mr and FMR flushing paths could race with additon and
removal.

List manipulation is done with RCU primatives and is protected by the
write side of a rwsem.  The list traversal in the get_mr fast path is
protected by a rcu read critical section.  The FMR list traversal is
more problematic because it can block while traversing the list.  We
protect this with the read side of the rwsem.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

Flushing FMRs is somewhat expensive, and is currently kicked off when
the interrupt handler notices that we are getting low.  The result of
this is that FMR flushing only happens from the interrupt cpus.

This spreads the load more effectively by triggering flushes just before
we allocate a new FMR.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

The trivial amount of memory saved isn't worth the cost of dealing with section
mismatches.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

This patch moves the FMR flushing work in to its own mult-threaded work queue.
This is to maintain performance in preparation for returning the main krdsd
work queue back to a single threaded work queue to avoid deep-rooted
concurrency bugs.

This is also good because it further separates FMRs, which might be removed
some day, from the rest of the code base.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

IB connections were not being destroyed during rmmod.

First, recently IB device removal callback was changed to disconnect
connections that used the removing device rather than destroying them.  So
connections with devices during rmmod were not being destroyed.

Second, rds_ib_destroy_nodev_conns() was being called before connections are
disassociated with devices.  It would almost never find connections in the
nodev list.

We first get rid of rds_ib_destroy_conns(), which is no longer called, and
refactor the existing caller into the main body of the function and get rid of
the list and lock wrappers.

Then we call rds_ib_destroy_nodev_conns() *after* ib_unregister_client() has
removed the IB device from all the conns and put the conns on the nodev list.

The result is that IB connections are destroyed by rmmod.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

Using a delayed work queue helps us make sure a healthy number of FMRs
have queued up over the limit.  It makes for a large improvement in RDMA
iops.

Signed-off-by: Chris Mason <chris.mason@oracle.com>