Commit Graph

69 Commits

Author SHA1 Message Date
Dave Jiang 84f766855f ntb: stop link work when we do not have memory
Instead of keep trying to go through the init routine when we aren't able
to allocate memory, we should just stop and go down.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2016-03-17 20:38:40 -04:00
Dave Jiang e902133162 ntb: stop tasklet from spinning forever during shutdown.
We can leave tasklet spinning forever if we disable the tasklet during
qp shutdown and the tasklets are still being kicked off. This hopefully
should avoid that race condition.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reported-by: Alex Depoutovitch <alex@pernixdata.com>
Tested-by: Alex Depoutovitch <alex@pernixdata.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2016-03-17 20:38:40 -04:00
Dave Jiang 8c874cc140 NTB: Address out of DMA descriptor issue with NTB
The transport right now does not handle the case where we run out of DMA
descriptors. We just fail when we do not succeed. Adding code to retry for
a bit attempting to use the DMA engine instead of instantly fail to CPU
copy.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2016-01-11 10:01:27 -05:00
Jon Mason 179f912a39 NTB: ntb_process_tx error path bug
The transmit overrun avoidance error path in ntb_process_tx accidentally
swapped the first two values being passed to the tx_handler client.
This could result in crashes in the ntb_netdev (or other out-of-tree NTB
clients).

Reported-by: Alex Depoutovitch <alex@pernixdata.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2016-01-11 09:51:17 -05:00
Arnd Bergmann fdcb4b2e78 NTB: fix 32-bit compiler warning
resource_size_t may be 32-bit wide on some architectures, which causes
this warning when building the NTB code:

drivers/ntb/ntb_transport.c: In function 'ntb_transport_link_work':
drivers/ntb/ntb_transport.c:828:46: warning: right shift count >= width of type [-Wshift-count-overflow]

The warning is harmless but can be avoided by using the upper_32_bits()
macro.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: e26a5843f7 ("NTB: Split ntb_hw_intel and ntb_transport drivers")
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08 16:24:43 -05:00
Jon Mason c92ba3c5d9 NTB: invalid buf pointer in multi-MW setups
Order of operations issue with the QP Num and MW count, which would
result in the receive buffer pointer being invalid if there are more
than 1 MW.  Corrected with parenthesis to enforce the proper order of
operations.

Reported-by: John I. Kading <John.Kading@gd-ms.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08 16:11:21 -05:00
Sudip Mukherjee 70d4687d60 NTB: remove unused variable
These variables were not used anywhere. So remove them.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08 16:11:21 -05:00
Sudip Mukherjee d4adee09fd NTB: fix access of free-ed pointer
We were accessing nt->mw_vec after freeing it. Fix the error path so
that we free nt->mw_vec after we have finished using it.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08 16:11:21 -05:00
Dave Jiang 04afde45e0 NTB: Fix issue where we may be accessing NULL ptr
smatch detected an issue in the function ntb_transport_max_size() where
we could be dereferencing a dma channel pointer when it is NULL.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-11-08 16:11:21 -05:00
Dave Jiang 569410ca75 NTB: Use unique DMA channels for TX and RX
Allocate two DMA channels, one for TX operation and one for RX
operation, instead of having one DMA channel for everything. This
provides slightly better performance, and also will make error handling
cleaner later on.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07 15:17:09 -04:00
Allen Hubbe 905921e748 NTB: Remove dma_sync_wait from ntb_async_rx
The dma_sync_wait can hurt the performance of workloads mixed with both
large and small frames.  Large frames will be copied using the dma
engine.  Small frames will be copied by the cpu.  The dma_sync_wait
prevents the cpu and dma engine copying in parallel.

In the period where the cpu is copying, the dma engine is stopped.  The
dma engine is not doing any useful work to copy large frames during that
time, and the additional time to restart the dma engine for the next
large frame.  This will decrease the throughput for the portion of a
workload with large frames.

In the period where the dma engine is copying, the cpu is held up
waiting for dma to complete.  The small frames processing will be
delayed until the dma is complete.  The RX frames are completed
in-order, and the processing of small frames takes very little time, so
dma_sync_wait may have an insignificant impact on the respose time of
frames.  The more significant impact is to the system, because the delay
in dma_sync_wait is implemented as busy non-blocking wait.  This can
prevent the delayed core from doing any useful work, even if it could be
processing work for other drivers, unrelated to transport RX processing.

After applying the earlier patch to fix out-of-order RX acknoledgement,
the dma_sync_wait is no longer necessary.  Remove it, so that cpu memcpy
will proceed immediately for small frames, in parallel with ongoing dma
for large frames.  Do not hold up the cpu from doing work while dma is
in progress.  The prior fix will continue to ensure in-order completion
of the RX frames to the upper layer, and in-order delivery of the RX
acknoledgement.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07 15:17:08 -04:00
Dave Jiang d98ef99e37 NTB: Clean up QP stats info
Make QP stats info more readable for debugging purposes.  Also add an
entry to indicate whether DMA is being used.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07 15:17:08 -04:00
Dave Jiang 315100004f NTB: Make the transport list in order of discovery
The list should be added from the bottom and not the top in order to
ensure the transport is provided in the same order to clients as ntb
devices are discovered.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07 15:17:08 -04:00
Dave Jiang e74bfeedad NTB: Add flow control to the ntb_netdev
Right now if we push the NTB really hard, we start dropping packets due
to not able to process the packets fast enough. We need to st:qop the
upper layer from flooding us when that happens.

A timer is necessary in order to restart the queue once the resource has
been processed on the receive side. Due to the way NTB is setup, the
resources on the tx side are tied to the processing of the rx side and
there's no async way to know when the rx side has released those
resources.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-09-07 15:17:08 -04:00
Allen Hubbe 30a4bb1e5a NTB: Fix dereference before check
Remove early dereference of a pointer that is checked later in the code.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09 16:32:22 -04:00
Allen Hubbe 8c9edf63e7 NTB: Fix zero size or integer overflow in ntb_set_mw
A plain 32 bit integer will overflow for values over 4GiB.

Change the plain integer size to the appropriate size type in
ntb_set_mw.  Change the type of the size parameter and two local
variables used for size.

Even if there is no overflow, a size of zero is invalid here.

Reported-by: Juyoung Jung <jjung@micron.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09 16:32:22 -04:00
Allen Hubbe 8b5a22d8f1 NTB: Schedule to receive on QP link up
Schedule to receive on QP link up, to make sure that the doorbell is
properly cleared for interrupts.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09 16:32:22 -04:00
Dave Jiang 260bee9451 NTB: Fix oops in debugfs when transport is half-up
When the remote side is not up, we do not have all the context for the
transport, and that causes NULL ptr access. Have the debugfs reads check
to see if transport is up before we make access.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09 16:32:22 -04:00
Dave Jiang c8650fd03d NTB: Fix transport stats for multiple devices
Currently the debugfs does not have files for all NTB transport queue
pairs.  When there are multiple NTBs present in a system, the QP names
of the last transport clobber the names of previously added transport
QPs.  Only the last added QPs can be observed via debugfs.

Create a directory per NTB transport to associate the QPs with that
transport.  Name the directory the same as the PCI device.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09 16:32:21 -04:00
Allen Hubbe da2e5ae561 NTB: Fix ntb_transport out-of-order RX update
It was possible for a synchronous update of the RX index in the error
case to get ahead of the asynchronous RX index update in the normal
case.  Change the RX processing to preserve an RX completion order.

There were two error cases.  First, if a buffer is not present to
receive data, there would be no queue entry to preserve the RX
completion order.  Instead of dropping the RX frame, leave the RX frame
in the ring.  Schedule RX processing when RX entries are enqueued, in
case there are RX frames waiting in the ring to be received.

Second, if a buffer is too small to receive data, drop the frame in the
ring, mark the RX entry as done, and indicate the error in the RX entry
length.  Check for a negative length in the receive callback in
ntb_netdev, and count occurrences as rx_length_errors.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-08-09 16:32:21 -04:00
Dave Jiang 7eb387813d NTB: Print driver name and version in module init
Printouts driver name and version to indicate what is being loaded.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:09:28 -04:00
Dave Jiang 9891417de8 NTB: Increase transport MTU to 64k from 16k
Benchmarking showed a significant performance increase with the MTU size
to 64k instead of 16k.  Change the driver default to 64k.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:09:27 -04:00
Dave Jiang a41ef053f7 NTB: Default to CPU memcpy for performance
Disable DMA usage by default, since the CPU provides much better
performance with write combining.  Provide a module parameter to enable
DMA usage when offloading the memcpy is preferred.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:09:24 -04:00
Dave Jiang 06917f7535 NTB: Improve performance with write combining
Changing the memory window BAR mappings to write combining significantly
boosts the performance.  We will also use memcpy that uses non-temporal
store, which showed performance improvement when doing non-cached
memcpys.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:09:21 -04:00
Allen Hubbe 1199aa6126 NTB: Use NUMA memory and DMA chan in transport
Allocate memory and request the DMA channel for the same NUMA node as
the NTB device.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:08:33 -04:00
Allen Hubbe 2876228941 NTB: Rate limit ntb_qp_link_work
When the ntb transport is connecting and waiting for the peer, the debug
console receives lots of debug level messages about the remote qp link
status being down.  Rate limit those messages.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:08:30 -04:00
Allen Hubbe 2849b5d706 NTB: Reset transport QP link stats on down
Reset the link stats when the link goes down.  In particular, the TX and
RX index and count must be reset, or else the TX side will be sending
packets to the RX side where the RX side is not expecting them.  Reset
all the stats, to be consistent.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:06:34 -04:00
Allen Hubbe c0900b33d1 NTB: Do not advance transport RX on link down
On link down, don't advance RX index to the next entry.  The next entry
should never be valid after receiving the link down flag.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:06:24 -04:00
Allen Hubbe e22e0b9dcf NTB: Differentiate transport link down messages
The same message "qp %d: Link Down\n" was printed at two locations in
ntb_transport.  Change the messages so they are distinct.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:06:19 -04:00
Dave Jiang 0f69a7dff9 NTB: Read peer info from local SPAD in transport
The transport was writing and then reading the peer scratch pad,
essentially reading what it just wrote instead of exchanging any
information with the peer.  The transport expects the peer values to be
the same as the local values, so this issue was not obvious.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:06:00 -04:00
Allen Hubbe e26a5843f7 NTB: Split ntb_hw_intel and ntb_transport drivers
Change ntb_hw_intel to use the new NTB hardware abstraction layer.

Split ntb_transport into its own driver.  Change it to use the new NTB
hardware abstraction layer.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-04 14:05:49 -04:00
Allen Hubbe ec110bc7cc NTB: Move files in preparation for NTB abstraction
This patch only moves files to their new locations, before applying the
next two patches adding the NTB Abstraction layer.  Splitting this patch
from the next is intended make distinct which code is changed only due
to moving the files, versus which are substantial code changes in adding
the NTB Abstraction layer.

Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2015-07-02 10:09:23 -04:00
Dave Jiang 3cc5ba1938 ntb: Add alignment check to meet hardware requirement
The NTB translate register must have the value to be BAR size aligned.
This alignment check make sure that the DMA memory allocated has the
proper alignment. Another requirement for NTB to function properly with
memory window BAR size greater or equal to 4M is to use the CMA feature
in 3.16 kernel with the appropriate CONFIG_CMA_ALIGNMENT and
CONFIG_CMA_SIZE_MBYTES set.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
2014-09-14 00:10:38 -04:00
Jon Mason a1413cfbcb NTB: correct the spread of queues over mw's
The detection of an uneven number of queues on the given memory windows
was not correct.  The mw_num is zero based and the mod should be
division to spread them evenly over the mw's.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2014-09-14 00:10:38 -04:00
Jon Mason 53ca4fea0b NTB: Code Style Clean-up
Some white space and 80 char overruns corrected.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2014-04-07 10:59:19 -07:00
Jon Mason 403c63cb6d NTB: client event cleanup
Provide a better event interface between the client and transport

Signed-off-by: Jon Mason <jon.mason@intel.com>
2014-04-07 10:59:19 -07:00
Linus Torvalds b95485143b NTB driver bug fixes to address a missed call to pci_enable_msix,
NTB-RP Link Up issue, Xeon Doorbell errata workaround, ntb_transport
 link down race, and correct dmaengine_get/put usage.  Also, clean-ups
 to remove duplicate defines and document a hardware errata.  Finally,
 some changes to improve performance.
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Merge tag 'ntb-3.13' of git://github.com/jonmason/ntb

Pull non-transparent bridge updates from Jon Mason:
 "NTB driver bug fixes to address a missed call to pci_enable_msix,
  NTB-RP Link Up issue, Xeon Doorbell errata workaround, ntb_transport
  link down race, and correct dmaengine_get/put usage.

  Also, clean-ups to remove duplicate defines and document a hardware
  errata.  Finally, some changes to improve performance"

* tag 'ntb-3.13' of git://github.com/jonmason/ntb:
  NTB: Disable interrupts and poll under high load
  NTB: Enable Snoop on Primary Side
  NTB: Document HW errata
  NTB: remove duplicate defines
  NTB: correct dmaengine_get/put usage
  NTB: Fix ntb_transport link down race
  ntb: Fix missed call to pci_enable_msix()
  NTB: Fix NTB-RP Link Up
  NTB: Xeon Doorbell errata workaround
2013-11-26 11:15:12 -08:00
Jon Mason e8aeb60c38 NTB: Disable interrupts and poll under high load
Disable interrupts and poll under high load

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-11-20 09:57:34 -07:00
Jon Mason 94681194e6 NTB: correct dmaengine_get/put usage
dmaengine_get() causes the initialization of the per-cpu channel tables.
It needs to be called prior to dma_find_channel().

Initial version by Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-11-20 09:57:32 -07:00
Jon Mason fca4d5188c NTB: Fix ntb_transport link down race
A WARN_ON is being hit in ntb_qp_link_work due to the NTB transport link
being down while the ntb qp link is still active.  This is caused by the
transport link being brought down prior to the qp link worker thread
being terminated.  To correct this, shutdown the qp's prior to bringing
the transport link down.  Also, only call the qp worker thread if it is
in interrupt context, otherwise call the function directly.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-11-20 09:57:32 -07:00
Bartlomiej Zolnierkiewicz 0776ae7b89 dmaengine: remove DMA unmap flags
Remove no longer needed DMA unmap flags:
- DMA_COMPL_SKIP_SRC_UNMAP
- DMA_COMPL_SKIP_DEST_UNMAP
- DMA_COMPL_SRC_UNMAP_SINGLE
- DMA_COMPL_DEST_UNMAP_SINGLE

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Jon Mason <jon.mason@intel.com>
Acked-by: Mark Brown <broonie@linaro.org>
[djbw: clean up straggling skip unmap flags in ntb]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2013-11-14 11:04:38 -08:00
Bartlomiej Zolnierkiewicz 6f57fd0578 NTB: convert to dmaengine_unmap_data
Use the generic unmap object to unmap dma buffers.

Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Tomasz Figa <t.figa@samsung.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Jon Mason <jon.mason@intel.com>
[djbw: fix up unmap len, and GFP flags]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2013-11-14 11:01:32 -08:00
Jon Mason f9a2cf890b NTB: Comment Fix
Add "data" ntb_register_db_callback parameter description comment and
correct poor spelling.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05 11:08:00 -07:00
Jon Mason 3daa3a073e NTB: Remove unused variable
Remove unused pci_dev variable from ntb_transport_free()

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05 11:07:59 -07:00
Jon Mason 497938890a NTB: Rename Variables for NTB-RP
Many variable names in the NTB driver refer to the primary or secondary
side.  However, these variables will be used to access the reverse case
when in NTB-RP mode.  Make these names more generic in anticipation of
NTB-RP support.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-05 11:07:58 -07:00
Jon Mason 282a2feeb9 NTB: Use DMA Engine to Transmit and Receive
Allocate and use a DMA engine channel to transmit and receive data over
NTB.  If none is allocated, fall back to using the CPU to transfer data.

Signed-off-by: Jon Mason <jon.mason@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
2013-09-05 11:04:09 -07:00
Jon Mason 948d3a65b6 NTB: Xeon Errata Workaround
There is a Xeon hardware errata related to writes to SDOORBELL or
B2BDOORBELL in conjunction with inbound access to NTB MMIO Space, which
may hang the system.  To workaround this issue, use one of the memory
windows to access the interrupt and scratch pad registers on the remote
system.  This bypasses the issue, but removes one of the memory windows
from use by the transport.  This reduction of MWs necessitates adding
some logic to determine the number of available MWs.

Since some NTB usage methodologies may have unidirectional traffic, the
ability to disable the workaround via modparm has been added.

See BF113 in
http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-c5500-c3500-spec-update.pdf
See BT119 in
http://www.intel.com/content/dam/www/public/us/en/documents/specification-updates/xeon-e5-family-spec-update.pdf

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03 13:51:51 -07:00
Jon Mason 1517a3f21a NTB: Correct debugfs to work with more than 1 NTB Device
Debugfs was setup in NTB to only have a single debugfs directory.  This
resulted in the leaking of debugfs directories and files when multiple
NTB devices were present, due to each device stomping on the variables
containing the previous device's values (thus preventing them from being
freed on cleanup).  Correct this by creating a secondary directory of
the PCI BDF for each device present, and nesting the previously existing
information in those directories.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-09-03 11:14:54 -07:00
Jon Mason 8b19d450ad
NTB: Multiple NTB client fix
Fix issue with adding multiple ntb client devices to the ntb virtual
bus.  Previously, multiple devices would be added with the same name,
resulting in crashes.  To get around this issue, add a unique number to
the device when it is added.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15 10:58:22 -07:00
Jon Mason c336acd333
NTB: memcpy lockup workaround
The system will appear to lockup for long periods of time due to the NTB
driver spending too much time in memcpy.  Avoid this by reducing the
number of packets that can be serviced on a given interrupt.

Signed-off-by: Jon Mason <jon.mason@intel.com>
2013-05-15 10:58:06 -07:00