~# strace -c dd if=/dev/sda of=/dev/null iflag=direct count=100k bs=4K
102400+0 records in
102400+0 records out
419430400 bytes (419 MB) copied, 4.95506 s, 84.6 MB/s
% time seconds usecs/call calls errors syscall
------ ----------- ----------- --------- --------- ----------------
94.88 0.006669 0 102403 read
5.12 0.000360 0 102403 write
0.00 0.000000 0 10 4 open
0.00 0.000000 0 9 close
0.00 0.000000 0 4 fstat
0.00 0.000000 0 1 lseek
0.00 0.000000 0 10 mmap
0.00 0.000000 0 4 mprotect
0.00 0.000000 0 2 munmap
0.00 0.000000 0 3 brk
0.00 0.000000 0 4 rt_sigaction
0.00 0.000000 0 3 3 access
0.00 0.000000 0 2 dup2
0.00 0.000000 0 1 execve
0.00 0.000000 0 1 arch_prctl
------ ----------- ----------- --------- --------- ----------------
100.00 0.007029 204860 7 total