Script SystemTap * :
#!/usr/bin/env stap
#
# Monitor the I/O of a program.
#
# Usage:
# ./monitor-io.stp name-of-the-program
global program_name = @1
probe begin {
printf("%5s %1s %6s %7s %s\n",
"PID", "D", "BYTES", "us", "FILE")
}
probe vfs.read.return, vfs.write.return {
# skip other programs
if (execname() != program_name)
next
if (devname=="N/A")
next
time_delta = gettimeofday_us() - @entry(gettimeofday_us())
direction = name == "vfs.read" ? "R" : "W"
# If you want only the filename, use
// filename = kernel_string($file->f_path->dentry->d_name->name)
# If you want only the path from the mountpoint, use
// filename = devname . "," . reverse_path_walk($file->f_path->dentry)
# If you want the full path, use
filename = task_dentry_path(task_current(),
$file->f_path->dentry,
$file->f_path->mnt)
printf("%5d %1s %6d %7d %s\n",
pid(), direction, $return, time_delta, filename)
}
Outputnya terlihat seperti ini:
[root@sl6 ~]# ./monitor-io.stp cat
PID D BYTES us FILE
3117 R 224 2 /lib/ld-2.12.so
3117 R 512 3 /lib/libc-2.12.so
3117 R 17989 700 /usr/share/doc/grub-0.97/COPYING
3117 R 0 3 /usr/share/doc/grub-0.97/COPYING
Atau jika Anda memilih untuk hanya menampilkan jalur dari titik mount:
[root@f19 ~]# ./monitor-io.stp cat
PID D BYTES us FILE
26207 R 392 4 vda3,usr/lib64/ld-2.17.so
26207 R 832 3 vda3,usr/lib64/libc-2.17.so
26207 R 1758 4 vda3,etc/passwd
26207 R 0 1 vda3,etc/passwd
26208 R 392 3 vda3,usr/lib64/ld-2.17.so
26208 R 832 3 vda3,usr/lib64/libc-2.17.so
26208 R 35147 16 vdb7,ciupicri/doc/grub2-2.00/COPYING
26208 R 0 2 vdb7,ciupicri/doc/grub2-2.00/COPYING
[root@f19 ~]# mount | grep -E '(vda3|vdb7)'
/dev/vda3 on / type ext4 (rw,relatime,seclabel,data=ordered)
/dev/vdb7 on /mnt/mnt1/mnt11/data type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
Keterbatasan / bug:
- mmap berbasis I / O tidak muncul karena
devnameis"N/A"
- file pada tmpfs tidak muncul karena
devnameitu"N/A"
- tidak masalah jika bacaan berasal dari cache atau tulis ke buffer
Hasil untuk program Matthew Ife :
untuk pribadi mmaptest :
PID D BYTES us FILE
3140 R 392 5 vda3,usr/lib64/ld-2.17.so
3140 R 832 5 vda3,usr/lib64/libc-2.17.so
3140 W 23 9 N/A,3
3140 W 23 4 N/A,3
3140 W 17 3 N/A,3
3140 W 17 118 N/A,3
3140 W 17 125 N/A,3
untuk mmaptest dibagikan:
PID D BYTES us FILE
3168 R 392 3 vda3,usr/lib64/ld-2.17.so
3168 R 832 3 vda3,usr/lib64/libc-2.17.so
3168 W 23 7 N/A,3
3168 W 23 2 N/A,3
3168 W 17 2 N/A,3
3168 W 17 98 N/A,3
untuk diotest (I / O langsung):
PID D BYTES us FILE
3178 R 392 2 vda3,usr/lib64/ld-2.17.so
3178 R 832 3 vda3,usr/lib64/libc-2.17.so
3178 W 16 6 N/A,3
3178 W 1048576 509 vda3,var/tmp/test_dio.dat
3178 R 1048576 244 vda3,var/tmp/test_dio.dat
3178 W 16 25 N/A,3
* Petunjuk pengaturan cepat untuk RHEL 6 atau yang setara: yum install systemtapdandebuginfo-install kernel