On 4/18/24 10:31, hexue wrote:
This patch is intended to release the CPU resources of io_uring in
polling mode. When IO is issued, the program immediately polls for
check completion, which is a waste of CPU resources when IO commands
are executed on the disk.
I add the hybrid polling feature in io_uring, enables polling to
release a portion of CPU resources without affecting block layer.
So that's basically the block layer hybrid polling, which, to
remind, was removed not that long ago, but moved into io_uring.
- Record the running time and context switching time of each
IO, and use these time to determine whether a process continue
to schedule.
- Adaptive adjustment to different devices. Due to the real-time
nature of time recording, each device's IO processing speed is
different, so the CPU optimization effect will vary.
- Set a interface (ctx->flag) enables application to choose whether
or not to use this feature.
The CPU optimization in peak workload of patch is tested as follows:
all CPU utilization of original polling is 100% for per CPU, after
optimization, the CPU utilization drop a lot (per CPU);
The first version was about cases that don't have iopoll queues.
How many IO poll queues did you have to get these numbers?
read(128k, QD64, 1Job) 37% write(128k, QD64, 1Job) 40%
randread(4k, QD64, 16Job) 52% randwrite(4k, QD64, 16Job) 12%
Compared to original polling, the optimised performance reduction
with peak workload within 1%.
read 0.29% write 0.51% randread 0.09% randwrite 0%
Reviewed-by: KANCHAN JOSHI <joshi.k@xxxxxxxxxxx>
Kanchan, did you _really_ take a look at the patch?
Signed-off-by: hexue <xue01.he@xxxxxxxxxxx>
---
include/linux/io_uring_types.h | 10 +++++
include/uapi/linux/io_uring.h | 1 +
io_uring/io_uring.c | 28 +++++++++++++-
io_uring/io_uring.h | 2 +
io_uring/rw.c | 69 ++++++++++++++++++++++++++++++++++
5 files changed, 109 insertions(+), 1 deletion(-)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 854ad67a5f70..7607fd8de91c 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -224,6 +224,11 @@ struct io_alloc_cache {
size_t elem_size;
};
--
Pavel Begunkov
