aio: Basic read_stream adjustments for real AIO Adapt the read stream logic for real AIO: - If AIO is enabled, we shouldn't issue advice, but if it isn't, we should continue issuing advice - AIO benefits from reading ahead with direct IO - If effective_io_concurrency=0, pass READ_BUFFERS_SYNCHRONOUSLY to StartReadBuffers() to ensure synchronous IO execution
There are further improvements we should consider: - While in read_stream_look_ahead(), we can use AIO batch submission mode for increased efficiency. That however requires care to avoid deadlocks and thus done separately. - It can be beneficial to defer starting new IOs until we can issue multiple IOs at once. That however requires non-trivial heuristics to decide when to do so. Reviewed-by: Noah Misch <n...@leadboat.com> Co-authored-by: Andres Freund <and...@anarazel.de> Co-authored-by: Thomas Munro <thomas.mu...@gmail.com> Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/f4d0730bbca1b338b8f06389d04816c6c9f06e58 Modified Files -------------- src/backend/storage/aio/read_stream.c | 39 +++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 13 deletions(-)
