rsyncrm

# mkdir testrm
# mkdir testrsync
# touch testrm/{1..100000}
# touch testrsync/{1..100000}

# time strace -c rsync -a --delete empty/ testrsync/ 2>&1
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
100.00    0.000017           3         5         3 wait4
  0.00    0.000000           0        15           read
  0.00    0.000000           0         6           write
  0.00    0.000000           0        11         3 open
  0.00    0.000000           0        10           close
  0.00    0.000000           0         1         1 stat
  0.00    0.000000           0         7           fstat
  0.00    0.000000           0         1           lstat
  0.00    0.000000           0        20           mmap
  0.00    0.000000           0        10           mprotect
  0.00    0.000000           0         2           munmap
  0.00    0.000000           0         3           brk
  0.00    0.000000           0        10           rt_sigaction
  0.00    0.000000           0         1           rt_sigprocmask
  0.00    0.000000           0         1         1 rt_sigreturn
  0.00    0.000000           0         6         6 access
  0.00    0.000000           0        19         1 select
  0.00    0.000000           0         2           socketpair
  0.00    0.000000           0         1           clone
  0.00    0.000000           0         1           execve
  0.00    0.000000           0        11           fcntl
  0.00    0.000000           0         2           getdents
  0.00    0.000000           0         1           getcwd
  0.00    0.000000           0         1           chdir
  0.00    0.000000           0         1           umask
  0.00    0.000000           0         6           gettimeofday
  0.00    0.000000           0         1           geteuid
  0.00    0.000000           0         1           arch_prctl
  0.00    0.000000           0         2           time
------ ----------- ----------- --------- --------- ----------------
100.00    0.000017                   158        15 total

real    0m1.548s
user    0m0.148s
sys 0m1.196s

# time strace -c rm -rf testrm 2>&1
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 64.01    0.017063           0    100001           unlinkat
 20.99    0.005595          58        97           getdents
 15.00    0.004000          18       218           brk
  0.00    0.000000           0         2           read
  0.00    0.000000           0         4           open
  0.00    0.000000           0         9           close
  0.00    0.000000           0         5           fstat
  0.00    0.000000           0         1           lstat
  0.00    0.000000           0         1         1 lseek
  0.00    0.000000           0        12           mmap
  0.00    0.000000           0         4           mprotect
  0.00    0.000000           0         4           munmap
  0.00    0.000000           0         1           ioctl
  0.00    0.000000           0         3         3 access
  0.00    0.000000           0         1           execve
  0.00    0.000000           0         7           fcntl
  0.00    0.000000           0         1           fstatfs
  0.00    0.000000           0         1           arch_prctl
  0.00    0.000000           0         1           openat
  0.00    0.000000           0         1           newfstatat
------ ----------- ----------- --------- --------- ----------------
100.00    0.026658                100374         4 total

real    0m6.724s
user    0m0.756s
sys 0m4.688s