Jens Axboe d7718a9d25 io_uring: use poll driven retry for files that support it ... Currently io_uring tries any request in a non-blocking manner, if it can, and then retries from a worker thread if we get -EAGAIN. Now that we have a new and fancy poll based retry backend, use that to retry requests if the file supports it. This means that, for example, an IORING_OP_RECVMSG on a socket no longer requires an async thread to complete the IO. If we get -EAGAIN reading from the socket in a non-blocking manner, we arm a poll handler for notification on when the socket becomes readable. When it does, the pending read is executed directly by the task again, through the io_uring task work handlers. Not only is this faster and more efficient, it also means we're not generating potentially tons of async threads that just sit and block, waiting for the IO to complete. The feature is marked with IORING_FEAT_FAST_POLL, meaning that async pollable IO is fast, and that poll<link>other_op is fast as well. Signed-off-by: Jens Axboe <axboe@kernel.dk>		2020-03-02 14:06:38 -07:00
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events	io_uring: use poll driven retry for files that support it	2020-03-02 14:06:38 -07:00
bpf_probe.h
define_trace.h
perf.h
syscall.h
trace_events.h	Tracing updates:	2020-02-06 07:12:11 +00:00