Replace calls to rxe_run_task() with rxe_sched_task(). This prevents the
tasks from all running on the same cpu.
This change slightly reduces performance for single qp send and write
benchmarks in loopback mode but greatly improves the performance with
multiple qps because if run task is used all the work tends to be
performed on one cpu. For actual on the wire benchmarks there is no
noticeable performance change.
Link: https://lore.kernel.org/r/20240329145513.35381-11-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Currently the rxe driver has three work queue tasks per qp. These are the
req.task, comp.task and resp.task which call rxe_requester(),
rxe_completer() and rxe_responder() respectively directly or on work
queues. Each of these subroutines checks to see if there is work to be
performed on the send queue or on the response packet queue or the request
packet queue and will run until there is no work remaining or yield the
cpu and reschedule itself until there is no work remaining.
This commit combines the req.task and comp.task into a single send.task
and renames the resp.task to the recv.task. The combined send.task calls
rxe_requester() and rxe_completer() serially and continues until all work
on both the send queue and the response packet queue are done.
In various benchmarks the performance is either improved or left the
same. At high scale there is a significant reduction in the load on the
cpu.
This is the first step in combining these two tasks. Once they are
serialized cross rescheduling of req.task and comp.task can be more
efficiently handled by just letting the send.task continue to run. This
will be done in the next several patches.
Link: https://lore.kernel.org/r/20240329145513.35381-7-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The IBA requires:
o11-5.2.5: If the HCA supports SRQ, for RC and UD service,
the CI shall generate a Last WQE Reached Affiliated Asynchronous
Event on a QP that is in the Error State and is associated with
an SRQ when either:
• a CQE is generated for the last WQE, or
• the QP gets in the Error State and there are no more
WQEs on the RQ.
This patch implements this behavior in flush_recv_queue() which is called
as a result of rxe_qp_error() being called whenever the qp is put into the
error state. The rxe responder executes SRQ WQEs directly from the SRQ so
there are never more WQES on the RQ.
Link: https://lore.kernel.org/r/20230602164229.9277-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
There is a reference count error in error path code and a potential race
in check_rkey() in rxe_resp.c. When looking up the rkey for a memory
window the reference to the mw from rxe_lookup_mw() is dropped before a
reference is taken on the mr referenced by the mw. If the mr is destroyed
immediately after the call to rxe_put(mw) the mr pointer is unprotected
and may end up pointing at freed memory. The rxe_get(mr) call should take
place before the rxe_put(mw) call.
All errors in check_rkey() call rxe_put(mw) if mw is not NULL but it was
already called after the above. The mw pointer should be set to NULL after
the rxe_put(mw) call to prevent this from happening.
Fixes: cdd0b85675 ("RDMA/rxe: Implement memory access through MWs")
Link: https://lore.kernel.org/r/20230517211509.1819998-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Currently the rxe driver makes little effort to make the changes to qp
state (which includes qp->attr.qp_state, qp->attr.sq_draining and
qp->valid) atomic between different client threads and IO threads. In
particular a common template is for an RDMA application to call
ib_modify_qp() to move a qp to ERR state and then wait until all the
packet and work queues have drained before calling ib_destroy_qp(). None
of these state changes are protected by locks to assure that the changes
are executed atomically and that memory barriers are included. This has
been observed to lead to incorrect behavior around qp cleanup.
This patch continues the work of the previous patches in this series and
adds locking code around qp state changes and lookups.
Link: https://lore.kernel.org/r/20230405042611.6467-5-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The rxe driver has four different QP state variables,
qp->attr.qp_state,
qp->req.state,
qp->comp.state, and
qp->resp.state.
All of these basically carry the same information.
This patch replaces uses of qp->resp.state by qp->attr.qp_state. This is
the first of three patches which will remove all but the qp->attr.qp_state
variable. This will bring the driver closer to the IBA description.
Link: https://lore.kernel.org/r/20230405042611.6467-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Currently each of the three tasklets requester, completer and responder in
the rxe driver take and release a reference to the qp argument at the
beginning and end of the subroutines. The caller passing in the qp
argument should be responsible for holding a reference to qp so these are
not required. Further doing so breaks the qp cleanup code in
rxe_qp_do_cleanup which calls these routines after all the references have
been dropped so they cannot drain the packet and work request queues as
intended.
In fact if these routines are deferred by calling tasklet_schedule there
is no guarantee that the calling code does have a qp reference. That is a
bug in rxe_task.c which will be fixed later in this series.
Link: https://lore.kernel.org/r/20230304174533.11296-6-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Originally is was thought that the tasklet machinery in rxe_task.c would
be used in other applications but that has not happened for years. This
patch replaces the 'void *arg' by struct 'rxe_qp *qp' in the parameters to
the tasklet calls. This change will have no affect on performance but may
make the code a little clearer.
Link: https://lore.kernel.org/r/20230304174533.11296-2-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This patch adds error and debug messages so that every interaction
with rdma-core through a verbs API call or a completion error return
will generate at least one error message backed up by debug messages
with more detail.
With dynamic debugging one can follow up after seeing an error message
by turning on the appropriate debug messages.
Link: https://lore.kernel.org/r/20230303221623.8053-5-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Currently the rxe driver does not handle all cases of zero length rdma
operations correctly. The client does not have to provide an rkey for zero
length RDMA read or write operations so the rkey provided may be invalid
and should not be used to lookup an mr.
This patch corrects the driver to ignore the provided rkey if the reth
length is zero for read or write operations and make sure to set the mr to
NULL. In read_reply() if length is zero rxe_recheck_mr() is not
called. Warnings are added in the routines in rxe_mr.c to catch NULL MRs
when the length is non-zero.
Fixes: 8700e3e7c4 ("Soft RoCE driver")
Link: https://lore.kernel.org/r/20230202044240.6304-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Reviewed-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Only the requested placement types that also registered in the destination
memory region are acceptable.
Otherwise, responder will also reply NAK "Remote Access Error" if it
found a placement type violation.
We will persist data via arch_wb_cache_pmem(), which could be
architecture specific.
This commit also adds 2 helpers to update qp.resp from the incoming packet.
Link: https://lore.kernel.org/r/20221206130201.30986-8-lizhijian@fujitsu.com
Reviewed-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Signed-off-by: Li Zhijian <lizhijian@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The code in rxe_resp.c at check_length() is incorrect as it compares
pkt->opcode an 8 bit value against various mask bits which are all higher
than 256 so nothing is ever reported.
This patch rewrites this to compare against pkt->mask which is
correct. However this now exposes another error. For UD send packets the
value of the pmtu cannot be determined from qp->mtu. All that is required
here is to later check if the payload fits into the posted receive buffer
in that case.
Fixes: 837a55847e ("RDMA/rxe: Implement packet length validation on responder")
Link: https://lore.kernel.org/r/20221208210945.28607-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Reviewed-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Make the execution of the atomic operation in rxe_atomic_reply()
conditional on res->replay and make duplicate_request() call into
rxe_atomic_reply() to merge the two flows. This is modeled on the behavior
of read reply. Delete the skb from the atomic responder resource since it
is no longer used. Adjust the reference counting of the qp in
send_atomic_ack() for this flow.
Fixes: 8700e3e7c4 ("Soft RoCE driver")
Link: https://lore.kernel.org/r/20220606143836.3323-6-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
In the tasklets (completer, responder, and requester) check the return
value from rxe_get() to detect failures to get a reference. This only
occurs if the qp has had its reference count drop to zero which indicates
that it no longer should be used.
The ref is never 0 today because the tasklets are flushed before the ref
is dropped. The next patch changes this so that the ref is dropped then
the tasklets are flushed.
Link: https://lore.kernel.org/r/20220421014042.26985-4-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The rping benchmark fails on long runs. The root cause of this failure has
been traced to a failure to compute a nonzero value of mr in rare
situations.
Fix this failure by correctly handling the computation of mr in
read_reply() in rxe_resp.c in the replay flow.
Fixes: 8a1a0be894 ("RDMA/rxe: Replace mr by rkey in responder resources")
Link: https://lore.kernel.org/r/20220418174103.3040-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The referenced commit generates a reference counting error if the rkey has
the same index but the wrong key. In this case the reference taken by
rxe_pool_get_index() is not dropped.
Drop the reference if the keys don't match in rxe_recheck_mr(). Check
that the mw and mr are still valid.
Fixes: 8a1a0be894 ("RDMA/rxe: Replace mr by rkey in responder resources")
Link: https://lore.kernel.org/r/20220411030647.20011-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
