pt-diskstats shows wrong device name

[Baron Schwartz]

pt-diskstats is showing the wrong device name. Sample file attached. Settings:

Sample output:

Enter a disk/device pattern: xvdb1
  #ts device rd_s rd_avkb rd_mb_s rd_mrg rd_cnc rd_rt wr_s wr_avkb wr_mb_s wr_mrg wr_cnc wr_rt busy in_prg io_s qtime stime
  1.0 ram0 258.9 42.4 10.7 0% 2.3 9.1 152.8 36.6 5.5 27% 2.7 12.9 50% 37 411.6 9.6 1.1
  2.0 ram0 177.3 40.3 7.0 0% 2.1 12.0 409.2 21.5 8.6 12% 3.6 7.7 69% 44 586.4 13.5 1.1
  3.0 ram0 135.0 39.9 5.3 0% 5.8 42.9 515.9 33.7 17.0 25% 18.9 27.6 97% 29 650.8 22.9 1.2
  4.0 ram0 272.5 42.0 11.2 0% 3.1 11.5 520.3 27.5 14.0 18% 7.4 11.7 78% 30 792.8 10.4 0.9
  5.0 ram0 207.4 40.6 8.2 0% 2.6 12.6 523.1 22.3 11.4 15% 7.1 11.5 86% 28 730.5 10.6 1.0

Notice that it's showing ram0 even though I told it to look only at xvdb1.

Current settings:

   You can control this program by key presses:
   ------------------- Key ------------------- ---- Current Setting ----
   A, D, S) Set the group-by mode S
   c) Enter a Perl regex to match column names .
   /) Enter a Perl regex to match disk names xvdb1
   z) Set the sample size in seconds 1
   i) Hide inactive disks yes
   p) Pause the program
   q) Quit the program
   space) Print headers
   ------------------- Press any key to continue -----------------------

Version:

# pt-diskstats --version
pt-diskstats 2.1.3

[Shahriyar Rzayev (rzayev-sehriyar)]

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PT-563