Skip to content

L
linux
Switch branch/tag
  1. 16 Feb, 2019 4 commits
  3. 15 Feb, 2019 5 commits
  5. 14 Feb, 2019 7 commits
  7. 13 Feb, 2019 4 commits
  9. 11 Feb, 2019 14 commits
  11. 09 Feb, 2019 5 commits
    • Doug Ledford's avatar
      Merge branch 'wip/dl-for-next' into for-next · 82771f20
      Doug Ledford authored 
      Due to concurrent work by myself and Jason, a normal fast forward merge
was not possible.  This brings in a number of hfi1 changes, mainly the
hfi1 TID RDMA support (roughly 10,000 LOC change), which was reviewed
and integrated over a period of days.
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
      82771f20
    • Doug Ledford's avatar
      Merge branch 'hfi1-tid' into wip/dl-for-next · 416fbc1b
      Doug Ledford authored 
      Omni-Path TID RDMA Feature

Intel Omni-Path (OPA) TID RDMA support is a feature that accelerates
data movement between two OPA nodes through the IB Verbs interface. It
improves RDMA READ/WRITE performance by delivering the data payload to a
user buffer directly without any software copying.

Architecture
=============
The TID RDMA protocol is implemented on the hfi1 driver level and is
therefore transparent to the ULPs. It is designed to facilitate the data
transactions for two specific RDMA requests:
  - RDMA READ;
  - RDMA WRITE.
Previously, when a verbs data packet is received at the destination
(requester side for RDMA READ and responder side for RDMA WRITE), the
data payload is copied to the user buffer by software, which slows down
the performance significantly for large requests.

Internally, hfi1 converts qualified RDMA READ/WRITE requests into TID
RDMA READ/WRITE requests when the requests are post sent to the hfi1
driver. Non-qualified RDMA requests are handled by normal RDMA protocol.

For TID RDMA requests, hardware resources (hardware flow and TID entries)
are allocated on the destination side (the requester side for TID RDMA
READ and the responder side for TID RDMA WRITE). The information for
these resources is conveyed to the data source side (the responder side
for TID RDMA READ and the requester side for TID RDMA WRITE) and embedded
in data packets. When data packets are received by the destination,
hardware will deliver the data payload to the destination buffer without
involving software and therefore improve the performance.

Details
=======
RDMA READ/WRITE requests are qualified by the following:
  - Total data length >= 256k;
  - Totoal data length is a multiple of 4K pages.

Additional qualifications are enforced for the destination buffers:
  For RDMA RAED:
    - Each destination sge buffer is 4K aligned;
    - Each destination sge buffer is a multiple of 4K pages.
  For RDMA WRITE:
    - The destination number is 4K aligned.

In addition, in an OPA fabric, some nodes may support TID RDMA while
others may not. As such, it is important for two transaction nodes to
exchange the information about the features they support. This discovery
mechanism is called OPA Feature Negotion (OPFN) and is described in
details in the patch series. Through OPFN, two nodes can find whether
they both support TID RDMA and subsequently convert RDMA requests into
TID RDMA requests.

* hfi1-tid: (46 commits)
  IB/hfi1: Prioritize the sending of ACK packets
  IB/hfi1: Add static trace for TID RDMA WRITE protocol
  IB/hfi1: Enable TID RDMA WRITE protocol
  IB/hfi1: Add interlock between TID RDMA WRITE and other requests
  IB/hfi1: Add TID RDMA WRITE functionality into RDMA verbs
  IB/hfi1: Add the dual leg code
  IB/hfi1: Add the TID second leg ACK packet builder
  IB/hfi1: Add the TID second leg send packet builder
  IB/hfi1: Resend the TID RDMA WRITE DATA packets
  IB/hfi1: Add a function to receive TID RDMA RESYNC packet
  IB/hfi1: Add a function to build TID RDMA RESYNC packet
  IB/hfi1: Add TID RDMA retry timer
  IB/hfi1: Add a function to receive TID RDMA ACK packet
  IB/hfi1: Add a function to build TID RDMA ACK packet
  IB/hfi1: Add a function to receive TID RDMA WRITE DATA packet
  IB/hfi1: Add a function to build TID RDMA WRITE DATA packet
  IB/hfi1: Add a function to receive TID RDMA WRITE response
  IB/hfi1: Add TID resource timer
  IB/hfi1: Add a function to build TID RDMA WRITE response
  IB/hfi1: Add functions to receive TID RDMA WRITE request
  ...
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
      416fbc1b
    • Raju Rangoju's avatar
      iw_cxgb4: fix srqidx leak during connection abort · f368ff18
      Raju Rangoju authored 
      When an application aborts the connection by moving QP from RTS to ERROR,
then iw_cxgb4's modify_rc_qp() RTS->ERROR logic sets the
*srqidxp to 0 via t4_set_wq_in_error(&qhp->wq, 0), and aborts the
connection by calling c4iw_ep_disconnect().

c4iw_ep_disconnect() does the following:
 1. sends up a close_complete_upcall(ep, -ECONNRESET) to libcxgb4.
 2. sends abort request CPL to hw.

But, since the close_complete_upcall() is sent before sending the
ABORT_REQ to hw, libcxgb4 would fail to release the srqidx if the
connection holds one. Because, the srqidx is passed up to libcxgb4 only
after corresponding ABORT_RPL is processed by kernel in abort_rpl().

This patch handle the corner-case by moving the call to
close_complete_upcall() from c4iw_ep_disconnect() to abort_rpl().  So that
libcxgb4 is notified about the -ECONNRESET only after abort_rpl(), and
libcxgb4 can relinquish the srqidx properly.
Signed-off-by: default avatarRaju Rangoju <rajur@chelsio.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      f368ff18
    • Raju Rangoju's avatar
      iw_cxgb4: complete the cached SRQ buffers · 11a27e21
      Raju Rangoju authored 
      If TP fetches an SRQ buffer but ends up not using it before the connection
is aborted, then it passes the index of that SRQ buffer to the host in
ABORT_REQ_RSS or ABORT_RPL CPL message.

But, if the srqidx field is zero in the received ABORT_RPL or
ABORT_REQ_RSS CPL, then we need to read the tcb.rq_start field to see if
it really did have an RQE cached. This works around a case where HW does
not include the srqidx in the ABORT_RPL/ABORT_REQ_RSS CPL.

The final value of rq_start is the one present in TCB with the
TF_RX_PDU_OUT bit cleared. So, we need to read the TCB, examine the
TF_RX_PDU_OUT (bit 49 of t_flags) in order to determine if there's a rx
PDU feedback event pending.
Signed-off-by: default avatarRaju Rangoju <rajur@chelsio.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      11a27e21
    • Raju Rangoju's avatar
      cxgb4: add tcb flags and tcb rpl struct · e381a1cb
      Raju Rangoju authored 
      This patch adds the tcb flags and structures needed for querying tcb
information.
Signed-off-by: default avatarRaju Rangoju <rajur@chelsio.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      e381a1cb
  13. 08 Feb, 2019 1 commit
    • Jason Gunthorpe's avatar
      RDMA/devices: Re-organize device.c locking · 921eab11
      Jason Gunthorpe authored 
      The locking here started out with a single lock that covered everything
and then has lately veered into crazy town.

The fundamental problem is that several places need to iterate over a
linked list, but also need to drop their locks to avoid deadlock during
client callbacks.

xarray's restartable iteration offers a simple solution to the
problem. Once all the lists are xarrays we can drop locks in the places
that need that and rely on xarray to provide consistency and locking for
the data structure.

The resulting simplification is that each of the three lists has a
dedicated rwsem that must be held when working with the list it
covers. One data structure is no longer covered by multiple locks.

The sleeping semaphore is selected because the read side generally needs
to be held over something sleeping, and using RCU reader locking in those
cases is overkill.

In the process this simplifies the entire registration/unregistration flow
to be the expected list of setups and the reversed list of matching
teardowns, and the registration lock 'refcount' can now be revised to be
released after the ULPs are removed, providing a very sane semantic for
this feature.
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
      921eab11
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7