> This sounds unexpected. Are there easy reproduction steps for this? Is > I/O definitely being processed by the lower levels of the kernel? I'm not sure how to reproduce it reliably. It seems to happen more often with NFS, not local filesystems. Here is an example where Ctrl-C does nothing. Then I ran "killall -9 fio" in another terminal" and it took about 20 seconds before the disk activity actually stopped in iostat. $ fio --name=write --rw=write --bs=1M --size=100G --end_fsync=1 --filename_format=/mnt/rivendell/fio.\$jobnum.\$filenum write: (g=0): rw=write, bs=(R) 1024KiB-1024KiB, (W) 1024KiB-1024KiB, (T) 1024KiB-1024KiB, ioengine=psync, iodepth=1 fio-3.1 Starting 1 process write: Laying out IO file (1 file / 102400MiB) fio: native_fallocate call failed: Operation not supported ^Cbs: 1 (f=1): [W(1)][14.3%][r=0KiB/s,w=1327MiB/s][r=0,w=1327 IOPS][eta 00m:42s] fio: terminating on signal 2 Killed1 (f=1): [F(1)][100.0%][r=0KiB/s,w=0KiB/s][r=0,w=0 IOPS][eta 00m:00s] $ ps aux | grep fio root 243211 36.0 0.0 931316 3068 ? Ds 14:25 0:08 fio --name=write --rw=write --bs=1M --size=100G --end_fsync=1 --filename_format=/mnt/rivendell/fio.$jobnum.$filenum root 243238 0.0 0.0 112708 988 pts/0 S+ 14:26 0:00 grep --color=auto fio
