Le 08/09/2021 à 14:33, Jens Axboe a écrit :
[..]
Same on a 5.10.35.
Jens, did we missed something here ?
Read through the actual thread. It seriously sounds like the system is
hitting bandwidth limits, which is very odd. 580K is not very much. Just
curious, does it change anything if you use 512b blocks instead?
That's clearly way better !
With default kernel config :
1 device : 512b : 674K
1 device: 512b + nomerge + nostats : 745K
1 device: 512b + nomerge + nostats + nopoll : 770K
2 devices, 2 thread + nopoll : taskset -c 0,1 t/io_uring -b512 -d128
-c32 -s32 -p0 -F1 -B1 -n2 /dev/nvme2n1 /dev/nvme3n1 : 1.57M
Enabling 32 poll queues:
1 device: 512b: 884K
1 device: 512b + nostats : 915K
1 device: 512b + nomerge + nostats + nopoll : 715K
2 devices, 2 thread nostats : taskset -c 0,1 t/io_uring -b512 -d128 -c32
-s32 -p1 -F1 -B1 -n2 /dev/nvme2n1 /dev/nvme3n1 : 1.84M
3 devices, 2 threads nostats : 2.2M
3 devices, 3 threads nostats : 2.8M
4 devices, 3 threads nostats 3.1M
4 devices, 4 threads nostats: 3.8M
Thanks for the insights !
Erwan,
