On 2/16/21 12:00 PM, Ober, Frank wrote: > Hi Daniel, Intel uses pvsync2 for QD1 testing so if you cannot use spdk or io_uring (these are the fastest ways to test a device), you can switch your engine to pvsync2 on this kernel and this will work. > > Here's what I tried on PCIe Gen3 system with an Optane drive and your drive. > > > [root@fm42adsdemo001 block]# fio --bs=1M --rw=randwrite --numjobs=1 --iodepth=1 --size=10000M \ >> --filename=/dev/nvme6n1 --name=mylittletest --direct=1 --fsync=1 \ >> --refill_buffers --ioengine=pvsync2 --group_reporting \ >> --fallocate=none --runtime=60 --time_based --hipri > mylittletest: (g=0): rw=randwrite, bs=(R) 1024KiB-1024KiB, (W) 1024KiB-1024KiB, (T) 1024KiB-1024KiB, ioengine=pvsync2, iodepth=1 > fio-3.24-5-g2ee2 > Starting 1 process > Jobs: 1 (f=1): [w(1)][100.0%][w=2048MiB/s][w=2048 IOPS][eta 00m:00s] > > I ran the same exact job on this mid-range Intel Xeon cpu and found io_uring only very slightly faster than pvsync2 > Jobs: 1 (f=1): [w(1)][100.0%][w=2057MiB/s][w=2057 IOPS][eta 00m:00s] That's not too surprising, if you're at queuedepth=1 or doing sync IO, then I'd consider it a major win that the async API is just as fast or faster than the sync one :-) -- Jens Axboe
