Skip to content

K
Kernel

openeuler / Kernel
1 年多 前同步成功

通知 8
Star 0
Fork 0
K
Kernel
切换分支/标签
  1. 02 3月, 2017 1 次提交
  3. 14 1月, 2017 1 次提交
    • P
      locking/atomic, kref: Add kref_read() · 2c935bc5
      由 Peter Zijlstra 提交于 
      Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>
      2c935bc5
  5. 11 1月, 2017 2 次提交
    • S
      iw_cxgb4: free EQ queue memory on last deref · c12a67fe
      由 Steve Wise 提交于 
      Commit ad61a4c7 ("iw_cxgb4: don't block in destroy_qp awaiting
the last deref") introduced a bug where the RDMA QP EQ queue memory
(and QIDs) are possibly freed before the underlying connection has been
fully shutdown.  The result being a possible DMA read issued by HW after
the queue memory has been unmapped and freed.  This results in possible
WR corruption in the worst case, system bus errors if an IOMMU is in use,
and SGE "bad WR" errors reported in the very least.  The fix is to defer
unmap/free of queue memory and QID resources until the QP struct has
been fully dereferenced.  To do this, the c4iw_ucontext must also be kept
around until the last QP that references it is fully freed.  In addition,
since the last QP deref can happen in an IRQ disabled context, we need
a new workqueue thread to do the final unmap/free of the EQ queue memory.

Fixes: ad61a4c7 ("iw_cxgb4: don't block in destroy_qp awaiting the last deref")
Cc: stable@vger.kernel.org
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>
      c12a67fe
    • S
      iw_cxgb4: refactor sq/rq drain logic · 4fe7c296
      由 Steve Wise 提交于 
      With the addition of the IB/Core drain API, iw_cxgb4 supported drain
by watching the CQs when the QP was out of RTS and signalling "drain
complete" when the last CQE is polled.  This, however, doesn't fully
support the drain semantics. Namely, the drain logic is supposed to signal
"drain complete" only when the application has _processed_ the last CQE,
not just removed them from the CQ.  Thus a small timing hole exists that
can cause touch after free type bugs in applications using the drain API
(nvmf, iSER, for example).  So iw_cxgb4 needs a better solution.

The iWARP Verbs spec mandates that "_at some point_ after the QP is
moved to ERROR", the iWARP driver MUST synchronously fail post_send and
post_recv calls.  iw_cxgb4 was currently not allowing any posts once the
QP is in ERROR.  This was in part due to the fact that the HW queues for
the QP in ERROR state are disabled at this point, so there wasn't much
else to do but fail the post operation synchronously.  This restriction
is what drove the first drain implementation in iw_cxgb4 that has the
above mentioned flaw.

This patch changes iw_cxgb4 to allow post_send and post_recv WRs after
the QP is moved to ERROR state for kernel mode users, thus still adhering
to the Verbs spec for user mode users, but allowing flush WRs for kernel
users.  Since the HW queues are disabled, we just synthesize a CQE for
this post, queue it to the SW CQ, and then call the CQ event handler.
This enables proper drain operations for the various storage applications.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>
      4fe7c296
  7. 17 11月, 2016 1 次提交
  9. 08 10月, 2016 1 次提交
  11. 16 9月, 2016 1 次提交
  13. 04 9月, 2016 1 次提交
  15. 03 8月, 2016 1 次提交
  17. 23 6月, 2016 3 次提交
  19. 14 5月, 2016 4 次提交
  21. 17 3月, 2016 1 次提交
  23. 02 3月, 2016 1 次提交
  25. 01 3月, 2016 1 次提交
  27. 24 12月, 2015 2 次提交
  29. 29 10月, 2015 2 次提交
  31. 31 8月, 2015 1 次提交
  33. 13 6月, 2015 1 次提交
  35. 12 6月, 2015 1 次提交
  37. 06 5月, 2015 1 次提交
  39. 19 2月, 2015 1 次提交
  41. 22 7月, 2014 1 次提交
  43. 16 7月, 2014 3 次提交
    • H
      cxgb4/iw_cxgb4: work request logging feature · 7730b4c7
      由 Hariprasad Shenai 提交于 
      This commit enhances the iwarp driver to optionally keep a log of rdma
work request timining data for kernel mode QPs.  If iw_cxgb4 module option
c4iw_wr_log is set to non-zero, each work request is tracked and timing
data maintained in a rolling log that is 4096 entries deep by default.
Module option c4iw_wr_log_size_order allows specifing a log2 size to use
instead of the default order of 12 (4096 entries). Both module options
are read-only and must be passed in at module load time to set them. IE:

modprobe iw_cxgb4 c4iw_wr_log=1 c4iw_wr_log_size_order=10

The timing data is viewable via the iw_cxgb4 debugfs file "wr_log".
Writing anything to this file will clear all the timing data.
Data tracked includes:

- The host time when the work request was posted, just before ringing
the doorbell.  The host time when the completion was polled by the
application.  This is also the time the log entry is created.  The delta
of these two times is the amount of time took processing the work request.

- The qid of the EQ used to post the work request.

- The work request opcode.

- The cqe wr_id field.  For sq completions requests this is the swsqe
index.  For recv completions this is the MSN of the ingress SEND.
This value can be used to match log entries from this log with firmware
flowc event entries.

- The sge timestamp value just before ringing the doorbell when
posting,  the sge timestamp value just after polling the completion,
and CQE.timestamp field from the completion itself.  With these three
timestamps we can track the latency from post to poll, and the amount
of time the completion resided in the CQ before being reaped by the
application.  With debug firmware, the sge timestamp is also logged by
firmware in its flowc history so that we can compute the latency from
posting the work request until the firmware sees it.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7730b4c7
    • H
      cxgb4/iw_cxgb4: use firmware ord/ird resource limits · 4c2c5763
      由 Hariprasad Shenai 提交于 
      Advertise a larger max read queue depth for qps, and gather the resource limits
from fw and use them to avoid exhaustinq all the resources.

Design:

cxgb4:

Obtain the max_ordird_qp and max_ird_adapter device params from FW
at init time and pass them up to the ULDs when they attach.  If these
parameters are not available, due to older firmware, then hard-code
the values based on the known values for older firmware.
iw_cxgb4:

Fix the c4iw_query_device() to report these correct values based on
adapter parameters.  ibv_query_device() will always return:

max_qp_rd_atom = max_qp_init_rd_atom = min(module_max, max_ordird_qp)
max_res_rd_atom = max_ird_adapter

Bump up the per qp max module option to 32, allowing it to be increased
by the user up to the device max of max_ordird_qp.  32 seems to be
sufficient to maximize throughput for streaming read benchmarks.

Fail connection setup if the negotiated IRD exhausts the available
adapter ird resources.  So the driver will track the amount of ird
resource in use and not send an RI_WR/INIT to FW that would reduce the
available ird resources below zero.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4c2c5763
    • H
      iw_cxgb4: Detect Ing. Padding Boundary at run-time · 04e10e21
      由 Hariprasad Shenai 提交于 
      Updates iw_cxgb4 to determine the Ingress Padding Boundary from
cxgb4_lld_info, and take subsequent actions.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NHariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      04e10e21
  45. 14 7月, 2014 1 次提交
  47. 11 6月, 2014 2 次提交
  49. 29 4月, 2014 1 次提交
    • S
      RDMA/cxgb4: Fix endpoint mutex deadlocks · cc18b939
      由 Steve Wise 提交于 
      In cases where the cm calls c4iw_modify_rc_qp() with the endpoint
mutex held, they must be called with internal == 1.  rx_data() and
process_mpa_reply() are not doing this.  This causes a deadlock
because c4iw_modify_rc_qp() might call c4iw_ep_disconnect() in some
!internal cases, and c4iw_ep_disconnect() acquires the endpoint mutex.
The design was intended to only do the disconnect for !internal calls.

Change rx_data(), FPDU_MODE case, to call c4iw_modify_rc_qp() with
internal == 1, and then disconnect only after releasing the mutex.

Change process_mpa_reply() to call c4iw_modify_rc_qp(TERMINATE) with
internal == 1 and set a new attr flag telling it to send a TERMINATE
message.  Previously this was implied by !internal.

Change process_mpa_reply() to return whether the caller should
disconnect after releasing the endpoint mutex.  Now rx_data() will do
the disconnect in the cases where process_mpa_reply() wants to
disconnect after the TERMINATE is sent.

Change c4iw_modify_rc_qp() RTS->TERM to only disconnect if !internal,
and to send a TERMINATE message if attrs->send_term is 1.

Change abort_connection() to not aquire the ep mutex for setting the
state, and make all calls to abort_connection() do so with the mutex
held.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>
      cc18b939
  51. 12 4月, 2014 1 次提交
  53. 21 3月, 2014 2 次提交
  55. 15 3月, 2014 1 次提交
    • S
      cxgb4/iw_cxgb4: Doorbell Drop Avoidance Bug Fixes · 05eb2389
      由 Steve Wise 提交于 
      The current logic suffers from a slow response time to disable user DB
usage, and also fails to avoid DB FIFO drops under heavy load. This commit
fixes these deficiencies and makes the avoidance logic more optimal.
This is done by more efficiently notifying the ULDs of potential DB
problems, and implements a smoother flow control algorithm in iw_cxgb4,
which is the ULD that puts the most load on the DB fifo.

Design:

cxgb4:

Direct ULD callback from the DB FULL/DROP interrupt handler.  This allows
the ULD to stop doing user DB writes as quickly as possible.

While user DB usage is disabled, the LLD will accumulate DB write events
for its queues.  Then once DB usage is reenabled, a single DB write is
done for each queue with its accumulated write count.  This reduces the
load put on the DB fifo when reenabling.

iw_cxgb4:

Instead of marking each qp to indicate DB writes are disabled, we create
a device-global status page that each user process maps.  This allows
iw_cxgb4 to only set this single bit to disable all DB writes for all
user QPs vs traversing the idr of all the active QPs.  If the libcxgb4
doesn't support this, then we fall back to the old approach of marking
each QP.  Thus we allow the new driver to work with an older libcxgb4.

When the LLD upcalls iw_cxgb4 indicating DB FULL, we disable all DB writes
via the status page and transition the DB state to STOPPED.  As user
processes see that DB writes are disabled, they call into iw_cxgb4
to submit their DB write events.  Since the DB state is in STOPPED,
the QP trying to write gets enqueued on a new DB "flow control" list.
As subsequent DB writes are submitted for this flow controlled QP, the
amount of writes are accumulated for each QP on the flow control list.
So all the user QPs that are actively ringing the DB get put on this
list and the number of writes they request are accumulated.

When the LLD upcalls iw_cxgb4 indicating DB EMPTY, which is in a workq
context, we change the DB state to FLOW_CONTROL, and begin resuming all
the QPs that are on the flow control list.  This logic runs on until
the flow control list is empty or we exit FLOW_CONTROL mode (due to
a DB DROP upcall, for example).  QPs are removed from this list, and
their accumulated DB write counts written to the DB FIFO.  Sets of QPs,
called chunks in the code, are removed at one time. The chunk size is 64.
So 64 QPs are resumed at a time, and before the next chunk is resumed, the
logic waits (blocks) for the DB FIFO to drain.  This prevents resuming to
quickly and overflowing the FIFO.  Once the flow control list is empty,
the db state transitions back to NORMAL and user QPs are again allowed
to write directly to the user DB register.

The algorithm is designed such that if the DB write load is high enough,
then all the DB writes get submitted by the kernel using this flow
controlled approach to avoid DB drops.  As the load lightens though, we
resume to normal DB writes directly by user applications.
Signed-off-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      05eb2389