Ubuntu on f2fs i/o test

bench.out

ii64@earth:/abc$ sudo fio --name=global --rw=randread --size=640m --name=job1 --name=job2
job1: (g=0): rw=randread, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=psync, iodepth=1
job2: (g=0): rw=randread, bs=(R) 4096B-4096B, (W) 4096B-4096B, (T) 4096B-4096B, ioengine=psync, iodepth=1
fio-3.29-99-g93365
Starting 2 processes
job1: Laying out IO file (1 file / 640MiB)
job2: Laying out IO file (1 file / 640MiB)
Jobs: 2 (f=2): [r(2)][91.7%][r=118MiB/s][r=30.2k IOPS][eta 00m:01s]
job1: (groupid=0, jobs=1): err= 0: pid=22040: Sat Feb 19 19:23:23 2022
  read: IOPS=15.0k, BW=58.5MiB/s (61.4MB/s)(640MiB/10931msec)
    clat (usec): min=29, max=2048, avg=61.50, stdev=12.42
     lat (usec): min=31, max=2051, avg=62.68, stdev=12.48
    clat percentiles (usec):
     |  1.00th=[   56],  5.00th=[   57], 10.00th=[   57], 20.00th=[   57],
     | 30.00th=[   58], 40.00th=[   58], 50.00th=[   58], 60.00th=[   59],
     | 70.00th=[   60], 80.00th=[   64], 90.00th=[   74], 95.00th=[   79],
     | 99.00th=[   98], 99.50th=[  110], 99.90th=[  172], 99.95th=[  217],
     | 99.99th=[  424]
   bw (  KiB/s): min=57448, max=60856, per=50.29%, avg=59939.81, stdev=854.75, samples=21
   iops        : min=14362, max=15214, avg=14984.95, stdev=213.69, samples=21
  lat (usec)   : 50=0.01%, 100=99.16%, 250=0.81%, 500=0.02%, 750=0.01%
  lat (msec)   : 4=0.01%
  cpu          : usr=1.35%, sys=23.50%, ctx=163916, majf=0, minf=11
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=163840,0,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=1
job2: (groupid=0, jobs=1): err= 0: pid=22041: Sat Feb 19 19:23:23 2022
  read: IOPS=14.9k, BW=58.2MiB/s (61.0MB/s)(640MiB/10998msec)
    clat (usec): min=20, max=674, avg=61.85, stdev=11.55
     lat (usec): min=21, max=675, avg=63.03, stdev=11.62
    clat percentiles (usec):
     |  1.00th=[   56],  5.00th=[   57], 10.00th=[   57], 20.00th=[   57],
     | 30.00th=[   58], 40.00th=[   58], 50.00th=[   58], 60.00th=[   59],
     | 70.00th=[   60], 80.00th=[   66], 90.00th=[   74], 95.00th=[   80],
     | 99.00th=[  102], 99.50th=[  115], 99.90th=[  174], 99.95th=[  208],
     | 99.99th=[  314]
   bw (  KiB/s): min=57248, max=60792, per=49.98%, avg=59565.71, stdev=895.23, samples=21
   iops        : min=14312, max=15198, avg=14891.43, stdev=223.81, samples=21
  lat (usec)   : 50=0.09%, 100=98.75%, 250=1.14%, 500=0.01%, 750=0.01%
  cpu          : usr=1.62%, sys=23.73%, ctx=163971, majf=0, minf=10
  IO depths    : 1=100.0%, 2=0.0%, 4=0.0%, 8=0.0%, 16=0.0%, 32=0.0%, >=64=0.0%
     submit    : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     complete  : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0%
     issued rwts: total=163840,0,0,0 short=0,0,0,0 dropped=0,0,0,0
     latency   : target=0, window=0, percentile=100.00%, depth=1

Run status group 0 (all jobs):
   READ: bw=116MiB/s (122MB/s), 58.2MiB/s-58.5MiB/s (61.0MB/s-61.4MB/s), io=1280MiB (1342MB), run=10931-10998msec

Disk stats (read/write):
  nvme0n1: ios=322869/3, merge=0/1, ticks=17331/0, in_queue=17331, util=99.01%