Chuck Lever 05eb06d866 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: 2fad659209 ("xprtrdma: Wait on empty sendctx queue") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>		2019-07-09 10:30:16 -04:00
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events	xprtrdma: Fix occasional transport deadlock	2019-07-09 10:30:16 -04:00
bpf_probe.h	bpf: add writable context for raw tracepoints	2019-04-26 19:04:19 -07:00
define_trace.h	tracing: introduce TRACE_EVENT_NOP()	2019-04-08 09:22:51 -04:00
perf.h
syscall.h
trace_events.h	tracing: Prevent further users of zero size static arrays in trace events	2018-05-29 08:29:13 -04:00