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  1. 05 Aug, 2016 2 commits
  3. 17 Mar, 2016 2 commits
  5. 11 Jan, 2016 2 commits
  7. 08 Nov, 2015 5 commits
  9. 07 Sep, 2015 5 commits
    • Dave Jiang's avatar
      NTB: Use unique DMA channels for TX and RX · 569410ca
      Dave Jiang authored 
      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: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
      569410ca
    • Allen Hubbe's avatar
      NTB: Remove dma_sync_wait from ntb_async_rx · 905921e7
      Allen Hubbe authored 
      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: default avatarAllen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
      905921e7
    • Dave Jiang's avatar
      NTB: Clean up QP stats info · d98ef99e
      Dave Jiang authored 
      Make QP stats info more readable for debugging purposes.  Also add an
entry to indicate whether DMA is being used.
Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
      d98ef99e
    • Dave Jiang's avatar
      NTB: Make the transport list in order of discovery · 31510000
      Dave Jiang authored 
      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: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
      31510000
    • Dave Jiang's avatar
      NTB: Add flow control to the ntb_netdev · e74bfeed
      Dave Jiang authored 
      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: default avatarDave Jiang <dave.jiang@intel.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
      e74bfeed
  11. 09 Aug, 2015 6 commits
  13. 04 Jul, 2015 11 commits
  15. 02 Jul, 2015 1 commit
  17. 13 Sep, 2014 2 commits
  19. 07 Apr, 2014 2 commits
  21. 20 Nov, 2013 2 commits