Some aspects of Tcl's filesystem (glob, file, pwd, cd primarily) became a bit slower with the vfs layer that was introduced in Tcl 8.4.0. This has gradually been addressed with later Tcl 8.4.x releases and also with Tcl 8.5.x. The current timings are as follows:
001 FILE dirname absolute tmpfile (obj) 8 10 0
002 FILE dirname absolute tmpfile (str) 11 14 10
003 FILE dirname relative tmpfile (obj) 8 11 0
004 FILE dirname relative tmpfile (str) 12 15 10
005 FILE dirname ~ 6 7 30
006 FILE exec interp 12652 12436 11820
007 FILE exec interp: exit 13463 12323 10920
008 FILE exec interp: pkg require 38329 67561 29940
009 FILE exec interp: pkg require+ 49142 93147 46400
010 FILE exec interp: pkg require+auto_path 53856 78622 43400
011 FILE exists tmpfile (obj) 20 20 20
012 FILE exists ~ 11 12 40
013 FILE exists! absolute tmpfile (obj) 17 18 20
014 FILE exists! absolute tmpfile (str) 23 199 20
015 FILE exists! relative tmpfile (obj) 14 18 20
016 FILE exists! relative tmpfile (str) 17 406 10
017 FILE exists! tmpfile (obj) 20 21 30
018 FILE exists! tmpfile (str) 26 351 20
019 FILE glob tmpdir (30 entries) / -dir 4380 5055 4600
020 FILE glob tmpdir (30 entries) / cd 5146 5458 4710
021 FILE glob tmpdir (subset of 30 entries) 2148 8242 4410
022 FILE glob / all subcommands 76189 60837 102150
023 FILE glob / atime 6771 7358 11210
024 FILE glob / attributes 45904 46978 43270
025 FILE glob / dirname 4398 5456 4800
026 FILE glob / executable 8607 6796 5810
027 FILE glob / exists 6277 6804 5810
028 FILE glob / extension 4338 5140 4610
029 FILE glob / isdirectory 6703 8396 11810
030 FILE glob / isfile 6959 7721 11420
031 FILE glob / mtime 6780 7310 11520
032 FILE glob / owned 6804 7635 11510
033 FILE glob / readable 11928 6794 5610
034 FILE glob / rootname 4411 5337 4710
035 FILE glob / size 7427 7106 11620
036 FILE glob / tail 4388 4973 4600
037 FILE glob / writable 10904 6807 5710
038 FILE glob deep dirs (30 entries+) 40638 53213 43570
039 FILE glob deep dirs (subset of 30 entries+) 22169 54320 42660
040 FILE glob dirs (30 entries) 4430 4582 11210
041 FILE recurse / -dir 94584 102725 128390
042 FILE recurse / cd 101832 163048 127880
043 FILE recurse+stat / -dir 116454 137213 232730
044 FILE recurse+stat / cd 138270 202646 244150
045 FILE tail absolute tmpfile (obj) 4 6 11
046 FILE tail absolute tmpfile (str) 7 11 0
047 FILE tail relative tmpfile (obj) 5 6 0
048 FILE tail relative tmpfile (str) 8 52 10
049 FILE tail ~ 4 7 20
049 BENCHMARKS 1:8.5a0 2:8.4.5 3:8.3.5(This is for a slightly modified version of file.bench, and a slightly modified version of Tcl 8.5a0 which is undergoing performance testing, where the above timings are on WinXP. Also see end of page for a normalized version).
If you have particular pieces of code using file, glob which are slower in Tcl 8.4/8.5, please add them to this page so that they can be added to the benchmark suite.
Note: reading from and writing to files is a totally separate topic, i.e. channel i/o, which has nothing to do with the vfs changes made to Tcl 8.4.0, and is therefore irrelevant to the particular benchmarking exercise on this page.
Note 2: the 'readable' and 'writable' benchmarks are slower because they actually return the correct values in Windows 2000/XP (Tcl 8.3/8.4 don't correctly check the more complex NTFS Windows user permissions).
Note 3: even with a new (hacked) version of tclbench which allows me to multiply the number of timed iterations by a factor of 10, I still see really huge variation in relative timings from one run to the next. For example, see the following two sets of normalized data, which should ostensibly be the same. Each benchmark is run somewhere between 300 and 10000 times to produce these.
Same data, normalized, run 1:
001 FILE dirname absolute tmpfile (obj) 1.75 2.50 1.00
002 FILE dirname absolute tmpfile (str) 2.20 2.80 1.00
003 FILE dirname relative tmpfile (obj) 1.60 2.20 1.00
004 FILE dirname relative tmpfile (str) 2.40 3.40 1.00
005 FILE dirname ~ 0.21 0.29 1.00
006 FILE exec interp 1.04 1.10 1.00
007 FILE exec interp: exit 1.09 1.16 1.00
008 FILE exec interp: pkg require 1.37 2.39 1.00
009 FILE exec interp: pkg require+ 1.02 1.99 1.00
010 FILE exec interp: pkg require+auto_path 1.19 2.04 1.00
011 FILE exists tmpfile (obj) 0.91 0.95 1.00
012 FILE exists ~ 0.33 0.36 1.00
013 FILE exists! absolute tmpfile (obj) 0.85 0.90 1.00
014 FILE exists! absolute tmpfile (str) 1.14 9.00 1.00
015 FILE exists! relative tmpfile (obj) 1.00 1.29 1.00
016 FILE exists! relative tmpfile (str) 1.06 20.81 1.00
017 FILE exists! tmpfile (obj) 0.83 0.88 1.00
018 FILE exists! tmpfile (str) 1.12 11.08 1.00
019 FILE glob tmpdir (30 entries) / -dir 0.96 1.01 1.00
020 FILE glob tmpdir (30 entries) / cd 1.06 1.15 1.00
021 FILE glob tmpdir (subset of 30 entries) 0.46 1.05 1.00
022 FILE glob / all subcommands 0.70 0.62 1.00
023 FILE glob / atime 0.58 0.63 1.00
024 FILE glob / attributes 1.06 1.10 1.00
025 FILE glob / dirname 0.90 1.12 1.00
026 FILE glob / executable 1.47 1.22 1.00
027 FILE glob / exists 1.12 1.22 1.00
028 FILE glob / extension 0.94 1.05 1.00
029 FILE glob / isdirectory 0.58 0.63 1.00
030 FILE glob / isfile 0.58 0.63 1.00
031 FILE glob / mtime 0.58 0.63 1.00
032 FILE glob / owned 0.58 0.63 1.00
033 FILE glob / readable 1.83 1.22 1.00
034 FILE glob / rootname 0.95 1.05 1.00
035 FILE glob / size 0.58 0.63 1.00
036 FILE glob / tail 0.92 1.07 1.00
037 FILE glob / writable 1.82 1.22 1.00
038 FILE glob deep dirs (30 entries+) 0.91 1.19 1.00
039 FILE glob deep dirs (subset of 30 entries+) 0.52 1.23 1.00
040 FILE glob dirs (30 entries) 0.38 0.41 1.00
041 FILE recurse / -dir 0.66 0.80 1.00
042 FILE recurse / cd 0.65 1.29 1.00
043 FILE recurse+stat / -dir 0.50 0.60 1.00
044 FILE recurse+stat / cd 0.49 0.91 1.00
045 FILE standard directory 'package require' 1.04 2.04 1.00
046 FILE tail absolute tmpfile (obj) 1.33 1.67 1.00
047 FILE tail absolute tmpfile (str) 2.00 2.25 1.00
048 FILE tail relative tmpfile (obj) 1.25 1.50 1.00
049 FILE tail relative tmpfile (str) 2.00 2.50 1.00
050 FILE tail ~ 0.17 0.22 1.00
050 BENCHMARKS 1:8.5a0 2:8.4.5 3:8.3.5
Same data, normalized, run 2:
001 FILE dirname absolute tmpfile (obj) 1.40 2.00 1.00
002 FILE dirname absolute tmpfile (str) 2.20 2.80 1.00
003 FILE dirname relative tmpfile (obj) 1.60 2.20 1.00
004 FILE dirname relative tmpfile (str) 2.40 3.60 1.00
005 FILE dirname ~ 0.26 0.30 1.00
006 FILE exec interp 1.06 1.11 1.00
007 FILE exec interp: exit 1.09 1.16 1.00
008 FILE exec interp: pkg require 1.38 2.39 1.00
009 FILE exec interp: pkg require+ 1.02 1.99 1.00
010 FILE exec interp: pkg require+auto_path 1.19 2.04 1.00
011 FILE exists tmpfile (obj) 0.95 1.00 1.00
012 FILE exists ~ 0.33 0.36 1.00
013 FILE exists! absolute tmpfile (obj) 0.90 0.90 1.00
014 FILE exists! absolute tmpfile (str) 1.05 8.59 1.00
015 FILE exists! relative tmpfile (obj) 0.93 1.29 1.00
016 FILE exists! relative tmpfile (str) 1.06 20.75 1.00
017 FILE exists! tmpfile (obj) 0.87 0.91 1.00
018 FILE exists! tmpfile (str) 1.13 11.54 1.00
019 FILE glob tmpdir (30 entries) / -dir 0.98 1.03 1.00
020 FILE glob tmpdir (30 entries) / cd 1.07 1.17 1.00
021 FILE glob tmpdir (subset of 30 entries) 0.46 1.05 1.00
022 FILE glob / all subcommands 0.70 0.63 1.00
023 FILE glob / atime 0.58 0.63 1.00
024 FILE glob / attributes 1.06 1.17 1.00
025 FILE glob / dirname 0.90 1.12 1.00
026 FILE glob / executable 1.48 1.23 1.00
027 FILE glob / exists 1.12 1.22 1.00
028 FILE glob / extension 0.95 1.06 1.00
029 FILE glob / isdirectory 0.58 0.63 1.00
030 FILE glob / isfile 0.58 0.63 1.00
031 FILE glob / mtime 0.58 0.63 1.00
032 FILE glob / owned 0.58 0.63 1.00
033 FILE glob / readable 1.83 1.22 1.00
034 FILE glob / rootname 0.95 1.05 1.00
035 FILE glob / size 0.58 0.63 1.00
036 FILE glob / tail 0.92 1.07 1.00
037 FILE glob / writable 1.83 1.22 1.00
038 FILE glob deep dirs (30 entries+) 0.92 1.20 1.00
039 FILE glob deep dirs (subset of 30 entries+) 0.52 1.23 1.00
040 FILE glob dirs (30 entries) 0.38 0.41 1.00
041 FILE recurse / -dir 0.66 0.80 1.00
042 FILE recurse / cd 0.66 1.29 1.00
043 FILE recurse+stat / -dir 0.50 0.60 1.00
044 FILE recurse+stat / cd 0.49 0.89 1.00
045 FILE standard directory 'package require' 1.05 2.06 1.00
046 FILE tail absolute tmpfile (obj) 1.33 2.33 1.00
047 FILE tail absolute tmpfile (str) 1.40 1.80 1.00
048 FILE tail relative tmpfile (obj) 1.67 2.00 1.00
049 FILE tail relative tmpfile (str) 1.60 2.00 1.00
050 FILE tail ~ 0.17 0.22 1.00
050 BENCHMARKS 1:8.5a0 2:8.4.5 3:8.3.5DGP 2004-01-22:
Working with the file.bench attached to Tcl Patch 871583, I can report that the news is not so good on Unix systems. A large commit yesterday did improve filesystem performance compared to before the patch, but comparing to 8.4 and 8.3 as above, the VFS still hurts:
000 VERSIONS: 1:8.5a0 2:8.5a0 3:8.4.5 4:8.3.5 001 FILE dirname absolute tmpfile (obj) 2.71 2.71 2.71 1.00 002 FILE dirname absolute tmpfile (str) 3.00 3.12 3.25 1.00 003 FILE dirname relative tmpfile (obj) 2.60 2.60 2.40 1.00 004 FILE dirname relative tmpfile (str) 2.83 3.17 3.17 1.00 005 FILE dirname ~ 0.11 0.11 0.10 1.00 006 FILE exec interp 1.15 1.14 1.09 1.00 007 FILE exec interp: exit 1.15 1.14 1.10 1.00 008 FILE exec interp: pkg require 1.40 1.39 1.36 1.00 009 FILE exec interp: pkg require+ 1.00 0.98 1.44 1.00 010 FILE exec interp: pkg require+auto_path 1.15 1.52 1.11 1.00 011 FILE exists tmpfile (obj) 1.14 1.14 1.29 1.00 012 FILE exists ~ 0.04 0.05 0.05 1.00 013 FILE exists! absolute tmpfile (obj) 0.54 0.62 0.62 1.00 014 FILE exists! absolute tmpfile (str) 1.50 3.17 4.83 1.00 015 FILE exists! relative tmpfile (obj) 0.83 1.33 1.33 1.00 016 FILE exists! relative tmpfile (str) 1.62 7.62 12.00 1.00 017 FILE exists! tmpfile (obj) 0.75 0.88 0.88 1.00 018 FILE exists! tmpfile (str) 1.70 3.00 4.20 1.00 019 FILE glob tmpdir (30 entries) / -dir 1.04 1.13 1.19 1.00 020 FILE glob tmpdir (30 entries) / cd 1.16 1.44 1.57 1.00 021 FILE glob tmpdir (subset of 30 entries) 0.97 1.00 1.03 1.00 022 FILE glob / all subcommands 1.00 1.02 1.00 1.00 023 FILE glob / atime 2.66 2.50 2.49 1.00 024 FILE glob / attributes 1.12 1.11 1.11 1.00 025 FILE glob / dirname 0.55 2.14 2.08 1.00 026 FILE glob / executable 2.60 2.50 2.46 1.00 027 FILE glob / exists 2.63 2.53 2.48 1.00 028 FILE glob / extension 0.99 1.63 1.59 1.00 029 FILE glob / isdirectory 2.58 2.54 2.49 1.00 030 FILE glob / isfile 2.57 2.46 2.45 1.00 031 FILE glob / mtime 2.59 2.47 2.43 1.00 032 FILE glob / owned 2.47 2.38 2.36 1.00 033 FILE glob / readable 2.61 2.53 2.45 1.00 034 FILE glob / rootname 1.18 1.71 1.64 1.00 035 FILE glob / size 2.59 2.50 2.49 1.00 036 FILE glob / tail 0.65 2.04 1.79 1.00 037 FILE glob / writable 2.66 2.54 2.49 1.00 038 FILE glob deep dirs (30 entries+) 1.12 1.20 1.34 1.00 039 FILE glob deep dirs (subset of 30 entries+) 0.98 1.08 1.18 1.00 040 FILE glob dirs (30 entries) 0.75 0.77 0.82 1.00 041 FILE recurse / -dir 2.12 2.17 2.16 1.00 042 FILE recurse / cd 1.17 2.79 2.99 1.00 043 FILE recurse+stat / -dir 1.34 1.35 1.37 1.00 044 FILE recurse+stat / cd 1.05 1.65 1.74 1.00 045 FILE standard directory 'package require' 1.42 1.33 1.60 1.00 046 FILE tail absolute tmpfile (obj) 2.00 2.20 2.00 1.00 047 FILE tail absolute tmpfile (str) 2.14 2.57 2.57 1.00 048 FILE tail relative tmpfile (obj) 2.25 2.25 2.25 1.00 049 FILE tail relative tmpfile (str) 2.80 3.20 3.40 1.00 050 FILE tail ~ 0.07 0.08 0.09 1.00 050 BENCHMARKS 1:8.5a0 2:8.5a0 3:8.4.5 4:8.3.5
Note that benchmarks 025 and 036 do show a speed improvement even over Tcl 8.3.5. Note also in the comment history of Tcl Patch 871583 that those are the only benchmarks that were specifically analyzed for improvements on Unix. I suspect there may be further improvements to achieve here. Just need someone on Unix to apply the effort the way Vince has done for Windows.
Vince: I've attached the file.bench with a few extra tests to the patch. I agree it would be great to do more work on Unix -- there are still too many things that are twice as slow. The interesting thing I noticed on Windows is that almost all the time is spent (60% in most benchmarks) in native normalization (checking whether directories exist and then finding their unique case-sensitive name and checking if they are a link). Certainly one would hope that Unix systems with 'realpath' should be much faster (assuming the realpath implementation is any good).