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| author | Michael J. Ruhl <michael.j.ruhl@intel.com> | 2018-09-20 12:59:14 -0700 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2018-09-20 19:24:51 -0600 |
| commit | b4a4957d3d1c328b733fce783b7264996f866ad2 (patch) | |
| tree | 030e57d01483ab424cf5d1e712077f8282cc5c7b /drivers/infiniband/hw/hfi1/pio.h | |
| parent | d623500b3c4efd8d4e945ac9003c6b87b469a9ab (diff) | |
| download | talos-op-linux-b4a4957d3d1c328b733fce783b7264996f866ad2.tar.gz talos-op-linux-b4a4957d3d1c328b733fce783b7264996f866ad2.zip | |
IB/hfi1: Fix destroy_qp hang after a link down
rvt_destroy_qp() cannot complete until all in process packets have
been released from the underlying hardware. If a link down event
occurs, an application can hang with a kernel stack similar to:
cat /proc/<app PID>/stack
quiesce_qp+0x178/0x250 [hfi1]
rvt_reset_qp+0x23d/0x400 [rdmavt]
rvt_destroy_qp+0x69/0x210 [rdmavt]
ib_destroy_qp+0xba/0x1c0 [ib_core]
nvme_rdma_destroy_queue_ib+0x46/0x80 [nvme_rdma]
nvme_rdma_free_queue+0x3c/0xd0 [nvme_rdma]
nvme_rdma_destroy_io_queues+0x88/0xd0 [nvme_rdma]
nvme_rdma_error_recovery_work+0x52/0xf0 [nvme_rdma]
process_one_work+0x17a/0x440
worker_thread+0x126/0x3c0
kthread+0xcf/0xe0
ret_from_fork+0x58/0x90
0xffffffffffffffff
quiesce_qp() waits until all outstanding packets have been freed.
This wait should be momentary. During a link down event, the cleanup
handling does not ensure that all packets caught by the link down are
flushed properly.
This is caused by the fact that the freeze path and the link down
event is handled the same. This is not correct. The freeze path
waits until the HFI is unfrozen and then restarts PIO. A link down
is not a freeze event. The link down path cannot restart the PIO
until link is restored. If the PIO path is restarted before the link
comes up, the application (QP) using the PIO path will hang (until
link is restored).
Fix by separating the linkdown path from the freeze path and use the
link down path for link down events.
Close a race condition sc_disable() by acquiring both the progress
and release locks.
Close a race condition in sc_stop() by moving the setting of the flag
bits under the alloc lock.
Cc: <stable@vger.kernel.org> # 4.9.x+
Fixes: 7724105686e7 ("IB/hfi1: add driver files")
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband/hw/hfi1/pio.h')
| -rw-r--r-- | drivers/infiniband/hw/hfi1/pio.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/pio.h b/drivers/infiniband/hw/hfi1/pio.h index 058b08f459ab..aaf372c3e5d6 100644 --- a/drivers/infiniband/hw/hfi1/pio.h +++ b/drivers/infiniband/hw/hfi1/pio.h @@ -139,6 +139,7 @@ struct send_context { #define SCF_IN_FREE 0x02 #define SCF_HALTED 0x04 #define SCF_FROZEN 0x08 +#define SCF_LINK_DOWN 0x10 struct send_context_info { struct send_context *sc; /* allocated working context */ @@ -306,6 +307,7 @@ void set_pio_integrity(struct send_context *sc); void pio_reset_all(struct hfi1_devdata *dd); void pio_freeze(struct hfi1_devdata *dd); void pio_kernel_unfreeze(struct hfi1_devdata *dd); +void pio_kernel_linkup(struct hfi1_devdata *dd); /* global PIO send control operations */ #define PSC_GLOBAL_ENABLE 0 |
