grpc_byte_buffer_reader_next() copies and references the slice. This
is not always necessary since the caller will not use the slice
after destroying the byte buffer.
A prominent example is the protobuf parser, which
calls grpc_byte_buffer_reader_next() and immediately unrefs the slice
after the call. This ref() and unref() calls can be very expensive
in the hot path.
This commit introduces grpc_byte_buffer_reader_peek() which
essentialy return a pointer to the slice in the buffer, i.e.,
no copies, and no refs.
QPS of 1MiB 1 Channel callback benchmark increases by 5%.
More importantly insructions per cycle is increased by 10%.
Also add tests and benchmarks for byte_buffer_reader_peek()
This commit reaplies 509e77a5a3
TCP_INQ is a socket option we added to Linux to report pending bytes
on the socket as a control message.
Using TCP_INQ we can accurately decide whether to continue read or not.
Add an urgent parameter, when we do not want to wait for EPOLLIN.
This commit improves the latency of 1 RPC unary (minimal benchmark)
significantly:
Before:
l_50: 61.3584984733
l_90: 94.8328711277
l_99: 126.211351174
l_999: 158.722406029
After:
l_50: 51.3546011488 (-16%)
l_90: 72.3420731581 (-23%)
l_99: 103.280218974 (-18%)
l_999: 130.905689996 (-17%)
grpc_byte_buffer_reader_next() copies and references the slice. This
is not always necessary since the caller will not use the slice
after destroying the byte buffer.
A prominent example is the protobuf parser, which
calls grpc_byte_buffer_reader_next() and immediately unrefs the slice
after the call. This ref() and unref() calls can be very expensive
in the hot path.
This commit introduces grpc_byte_buffer_reader_peek() which
essentialy return a pointer to the slice in the buffer, i.e.,
no copies, and no refs.
QPS of 1MiB 1 Channel callback benchmark increases by 5%.
More importantly insructions per cycle is increased by 10%.
Also add tests and benchmarks for byte_buffer_reader_peek()
Add a utility function in iomgr to check whether the caller thread is a
worker for any background poller, and keep grpc combiner from offloading
closures to the default executor if the current thread is a worker for
any background poller.
Karthik Ravi Shankar