/openbmc/linux/include/trace/events/ |
H A D | rpcrdma.h | 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock
Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.
I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible.
Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed.
Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it.
Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy. I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible. Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed. Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it. Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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/openbmc/linux/net/sunrpc/xprtrdma/ |
H A D | frwr_ops.c | 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock
Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.
I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible.
Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed.
Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it.
Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy. I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible. Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed. Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it. Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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H A D | rpc_rdma.c | 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock
Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.
I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible.
Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed.
Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it.
Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy. I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible. Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed. Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it. Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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H A D | xprt_rdma.h | 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock
Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.
I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible.
Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed.
Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it.
Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy. I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible. Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed. Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it. Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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H A D | verbs.c | 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock
Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy.
I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible.
Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed.
Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it.
Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com> 05eb06d8 Wed Jun 19 09:32:48 CDT 2019 Chuck Lever <chuck.lever@oracle.com> xprtrdma: Fix occasional transport deadlock Under high I/O workloads, I've noticed that an RPC/RDMA transport occasionally deadlocks (IOPS goes to zero, and doesn't recover). Diagnosis shows that the sendctx queue is empty, but when sendctxs are returned to the queue, the xprt_write_space wake-up never occurs. The wake-up logic in rpcrdma_sendctx_put_locked is racy. I noticed that both EMPTY_SCQ and XPRT_WRITE_SPACE are implemented via an atomic bit. Just one of those is sufficient. Removing EMPTY_SCQ in favor of the generic bit mechanism makes the deadlock un-reproducible. Without EMPTY_SCQ, rpcrdma_buffer::rb_flags is no longer used and is therefore removed. Unfortunately this patch does not apply cleanly to stable. If needed, someone will have to port it and test it. Fixes: 2fad659209d5 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
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