Commit Graph

29 Commits

Author SHA1 Message Date
Huang Ying 1bc144b625 net, rds, Replace xlist in net/rds/xlist.h with llist
The functionality of xlist and llist is almost same.  This patch
replace xlist with llist to avoid code duplication.

Known issues: don't know how to test this, need special hardware?

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Andy Grover <andy.grover@oracle.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-15 15:36:32 -04:00
Tejun Heo c534a107e8 rds/ib: use system_wq instead of rds_ib_fmr_wq
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>
2011-02-01 11:42:43 +01:00
stephen hemminger ff51bf8415 rds: make local functions/variables static
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>
2010-10-21 04:26:39 -07:00
Dan Carpenter aef3ea33e8 rds: spin_lock_irq() is not nestable
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>
2010-09-19 11:59:44 -07:00
Zach Brown ea819867b7 RDS/IB: protect the list of IB devices
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>
2010-09-08 18:16:44 -07:00
Chris Mason 8576f374ac RDS: flush fmrs before allocating new ones
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>
2010-09-08 18:16:42 -07:00
Zach Brown ef87b7ea39 RDS: remove __init and __exit annotation
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>
2010-09-08 18:16:39 -07:00
Zach Brown 515e079dab RDS/IB: create a work queue for FMR flushing
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>
2010-09-08 18:16:34 -07:00
Zach Brown 8aeb1ba663 RDS/IB: destroy connections on rmmod
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>
2010-09-08 18:16:33 -07:00
Andy Grover c9455d9996 RDS: whitespace 2010-09-08 18:15:32 -07:00
Chris Mason 7a0ff5dbdd RDS: use delayed work for the FMR flushes
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>
2010-09-08 18:15:30 -07:00
Chris Mason 6fa70da608 rds: recycle FMRs through lockless lists
FRM allocation and recycling is performance critical and fairly lock
intensive.  The current code has a per connection lock that all
processes bang on and it becomes a major bottleneck on large systems.

This changes things to use a number of cmpxchg based lists instead,
allowing us to go through the whole FMR lifecycle without locking inside
RDS.

Zach Brown pointed out that our usage of cmpxchg for xlist removal is
racey if someone manages to remove and add back an FMR struct into the list
while another CPU can see the FMR's address at the head of the list.

The second CPU might assume the list hasn't changed when in fact any
number of operations might have happened in between the deletion and
reinsertion.

This commit maintains a per cpu count of CPUs that are currently
in xlist removal, and establishes a grace period to make sure that
nobody can see an entry we have just removed from the list.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08 18:15:28 -07:00
Zach Brown 3e0249f9c0 RDS/IB: add refcount tracking to struct rds_ib_device
The RDS IB client .remove callback used to free the rds_ibdev for the given
device unconditionally.  This could race other users of the struct.  This patch
adds refcounting so that we only free the rds_ibdev once all of its users are
done.

Many rds_ibdev users are tied to connections.  We give the connection a
reference and change these users to reference the device in the connection
instead of looking it up in the IB client data.  The only user of the IB client
data remaining is the first lookup of the device as connections are built up.

Incrementing the reference count of a device found in the IB client data could
race with final freeing so we use an RCU grace period to make sure that freeing
won't happen until those lookups are done.

MRs need the rds_ibdev to get at the pool that they're freed in to.  They exist
outside a connection and many MRs can reference different devices from one
socket, so it was natural to have each MR hold a reference.  MR refs can be
dropped from interrupt handlers and final device teardown can block so we push
it off to a work struct.  Pool teardown had to be fixed to cancel its pending
work instead of deadlocking waiting for all queued work, including itself, to
finish.

MRs get their reference from the global device list, which gets a reference.
It is left unprotected by locks and remains racy.  A simple global lock would
be a significant bottleneck.  More scalable (complicated) locking should be
done carefully in a later patch.

Signed-off-by: Zach Brown <zach.brown@oracle.com>
2010-09-08 18:15:17 -07:00
Chris Mason 38a4e5e613 rds: Use RCU for the bind lookup searches
The RDS bind lookups are somewhat expensive in terms of CPU
time and locking overhead.  This commit changes them into a
faster RCU based hash tree instead of the rbtrees they were using
before.

On large NUMA systems it is a significant improvement.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08 18:15:08 -07:00
Andy Grover e4c52c98e0 RDS/IB: add _to_node() macros for numa and use {k,v}malloc_node()
Allocate send/recv rings in memory that is node-local to the HCA.
This significantly helps performance.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:14:06 -07:00
Andy Grover 4a81802b5e RDS/IB: Remove unused variable in ib_remove_addr()
Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:12:29 -07:00
Chris Mason 764f2dd92f rds: rcu-ize rds_ib_get_device()
rds_ib_get_device is called very often as we turn an
ip address into a corresponding device structure.  It currently
take a global spinlock as it walks different lists to find active
devices.

This commit changes the lists over to RCU, which isn't very complex
because they are not updated very often at all.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08 18:12:28 -07:00
Andy Grover 15133f6e67 RDS: Implement atomic operations
Implement a CMSG-based interface to do FADD and CSWP ops.

Alter send routines to handle atomic ops.

Add atomic counters to stats.

Add xmit_atomic() to struct rds_transport

Inline rds_ib_send_unmap_rdma into unmap_rm

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:41 -07:00
Andy Grover 21f79afa5f RDS: fold rdma.h into rds.h
RDMA is now an intrinsic part of RDS, so it's easier to just have
a single header.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:11:37 -07:00
Andy Grover 9e2effba2c RDS: Fix BUG_ONs to not fire when in a tasklet
in_interrupt() is true in softirqs. The BUG_ONs are supposed
to check for if irqs are disabled, so we should use
BUG_ON(irqs_disabled()) instead, duh.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
2010-09-08 18:07:31 -07:00
David S. Miller 871039f02f Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/stmmac/stmmac_main.c
	drivers/net/wireless/wl12xx/wl1271_cmd.c
	drivers/net/wireless/wl12xx/wl1271_main.c
	drivers/net/wireless/wl12xx/wl1271_spi.c
	net/core/ethtool.c
	net/mac80211/scan.c
2010-04-11 14:53:53 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Andy Grover 561c7df63e RDS: Do not call set_page_dirty() with irqs off
set_page_dirty() unconditionally re-enables interrupts, so
if we call it with irqs off, they will be on after the call,
and that's bad. This patch moves the call after we've re-enabled
interrupts in send_drop_to(), so it's safe.

Also, add BUG_ONs to let us know if we ever do call set_page_dirty
with interrupts off.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16 21:17:01 -07:00
Andy Grover 571c02fa81 RDS: Workaround for in-use MRs on close causing crash
if a machine is shut down without closing sockets properly, and
freeing all MRs, then a BUG_ON will bring it down. This patch
changes these to WARN_ONs -- leaking MRs is not fatal (although
not ideal, and there is more work to do here for a proper fix.)

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-16 21:16:56 -07:00
Joe Perches f64f9e7192 net: Move && and || to end of previous line
Not including net/atm/

Compiled tested x86 allyesconfig only
Added a > 80 column line or two, which I ignored.
Existing checkpatch plaints willfully, cheerfully ignored.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-29 16:55:45 -08:00
Andy Grover 433d308dd8 RDS: Fix panic on unload
Remove explicit destruction of passive connection when destroying
active end of the connection. The passive end is also on the
device's connection list, and will thus be cleaned up properly.
Panic was caused by trying to clean it up twice.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-30 15:06:38 -07:00
Andy Grover a870d62726 RDS/IB: Always use PAGE_SIZE for FMR page size
While FMRs allow significant flexibility in what size of pages they can use,
we really just want FMR pages to match CPU page size. Roland says we can
count on this always being supported, so this simplifies things.

Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-20 08:03:13 -07:00
Andy Grover 745cbccac3 RDS: Rewrite connection cleanup, fixing oops on rmmod
This fixes a bug where a connection was unexpectedly
not on *any* list while being destroyed. It also
cleans up some code duplication and regularizes some
function names.

* Grab appropriate lock in conn_free() and explain in comment
* Ensure via locking that a conn is never not on either
  a dev's list or the nodev list
* Add rds_xx_remove_conn() to match rds_xx_add_conn()
* Make rds_xx_add_conn() return void
* Rename remove_{,nodev_}conns() to
  destroy_{,nodev_}conns() and unify their implementation
  in a helper function
* Document lock ordering as nodev conn_lock before
  dev_conn_lock

Reported-by: Yosef Etigin <yosefe@voltaire.com>
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-02 00:52:22 -07:00
Andy Grover 08b48a1ed8 RDS/IB: Implement RDMA ops using FMRs
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-26 23:39:31 -08:00