Department of Computer Science
University of São Paulo
São Paulo, Brazil

Compression and Performance Statistics

On this page you can find some of our compression tests on swapped out pages in Linux 2.4. This page was created to help us out visualize and make some analysis on these data. WARNING: this material is still very raw and some numbers may not be correct due to unpredictable situations. If you have any suggestions or opinion, please send an e-mail to us at linuxcompressed-devel@lists.sourceforge.net.

Configuration

AMD K6-2 400 MHz
256 Mb RAM
256 Mb Swap
Kernel Host: 2.4.5-ac15
Kernels tested (all UML patched):
- 2.4.5 Linux Kernel + 2.4.5-11um UML patch + 0.16 Compressed Cache (features asynchronous swap out)
- 2.4.5 Linux Kernel + 2.4.5-11um UML patch + 0.16 Compressed Cache - Asynchronous Swap Out Features
- 2.4.5 Linux Kernel + 2.4.5-11um UML patch
UML configuration: 16 Mb RAM + 32 Mb Swap file
Compression Algorithm: WKdm

Tests Run (from Memtest Suite)

mmap001

1 time

command:
```
time ./mmap001 40
```

2.4.5 + 0.16 comp cache 500 pages (asynchronous swap out)

real    0m26.157s (second try = 24.503s)
user    0m0.550s
sys     0m2.550s

pgpgin = 9744
pgpgout = 83694
pswpin = 1
pswpout = 0

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
241
-- size --
min        | max        | mean     
       276 |       3800 |        1272
-- compression cycles --
min        | max        | mean
     27446 |    4686189 |       57325
-- decompression cycles --
min        | max        | mean
     18676 |      53858 |        8456
	 
compression ratio:       31%
discarded pages:          5
discarded ratio:          2%

CVS as of Jul 3rd 2001: 2.4.5 + 0.16 comp cache + Hash Table

real    0m17.172s
user    0m0.400s
sys     0m2.650s

2.4.5 + 0.16 comp cache 500 pages (synchronous swap out)

real    0m36.398s (second try = 39s)
user    0m0.500s
sys     0m3.350s

pgpgin = 10028
pgpgout = 83524
pswpin = 1
pswpout = 0

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
251
-- size --
min        | max        | mean     
       276 |       3800 |        1258
-- compression cycles --
min        | max        | mean
     26459 |    4940508 |       57029
-- decompression cycles --
min        | max        | mean
     16959 |      47305 |        8010
	 
compression ratio:       30%
discarded pages:          5
discarded ratio:          1%

2.4.5 vanilla

real    0m56.173s
user    0m0.250s
sys     0m4.400s

pgpgin = 11024
pgpgout = 85132 
pswpin = 184
pswpout = 240

mmap001

26 times

command:

time for i in `seq 0 25`; do echo $i;
      ./mmap001 40; done

2.4.5 + 0.16 comp cache 500 pages (asynchronous swap out)

real    8m9.772s
user    0m19.250s
sys     1m3.300s

pgpgin = 70390
pgpgout = 2148338
pswpin = 1
pswpout = 0

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
1859
-- size --
min        | max        | mean     
       272 |       3800 |        1499
-- compression cycles --
min        | max        | mean
     28633 |    8025798 |       61009
-- decompression cycles --
min        | max        | mean
     17332 |    1785363 |       27410
 
compression ratio:       36%
discarded pages:         30
discarded ratio:          1%

CVS as of Jul 3rd 2001: 2.4.5 + 0.16 comp cache + Hash Table

real    7m6.528s
user    0m17.450s
sys     1m1.700s

2.4.5 + 0.16 comp cache 500 pages (synchronous swap out)

real    8m17.430s
user    0m20.850s
sys     1m9.200s

pgpgin = 71714
pgpgout = 2147956
pswpin = 1
pswpout = 0

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
1861
-- size --
min        | max        | mean     
       272 |       3800 |        1510
-- compression cycles --
min        | max        | mean
     28808 |    3848968 |       63041
-- decompression cycles --
min        | max        | mean
     18310 |    3113619 |       27477
 
compression ratio:       36%
discarded pages:         30
discarded ratio:          1%

2.4.5 vanilla

real    9m2.248s
user    0m18.800s  
sys     1m6.000s

pgpgin = 90198
pgpgout = 2156814
pswpin = 2691
pswpout = 1103

fillmem

1 time

command:
```
time ./fillmem 40
```

2.4.5 + 0.16 comp cache 500 pages (asynchronous swap out)

   
real    0m56.526s
user    0m0.450s
sys     0m21.800s

pgpgin = 56834
pgpgout = 82282
pswpin = 5553
pswpout = 10246

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
14840
-- size --
min        | max        | mean     
       272 |       3800 |         785
-- compression cycles --
min        | max        | mean
     24864 |   24536956 |       33761
-- decompression cycles --
min        | max        | mean
     11502 |    4654698 |       18826
	 
compression ratio:       19%
discarded pages:          5
discarded ratio:          0%

CVS as of Jul 3rd 2001: 2.4.5 + 0.16 comp cache + Hash Table


real    0m29.132s
user    0m0.350s
sys     0m2.800s

2.4.5 + 0.16 comp cache 500 pages (synchronous swap out)

real    1m14.772s
user    0m0.700s
sys     0m21.950s

pgpgin = 56826
pgpgout = 81582
pswpin = 5524 
pswpout = 10160

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
14848
-- size --
min        | max        | mean     
       272 |       3800 |         785
-- compression cycles --
min        | max        | mean
     24895 |    5114996 |       36082
-- decompression cycles --
min        | max        | mean
     14772 |    2419087 |       20853
  	 
compression ratio:       19%
discarded pages:          5
discarded ratio:          0%

2.4.5 vanilla

real    0m22.766s
user    0m1.500s
sys     0m2.300s

pgpgin = 67800
pgpgout = 111656
pswpin = 7209
pswpout = 13918

fillmem

26 times

command:

time for i in `seq 0 25`; do echo $i;
       ./fillmem 40; done

2.4.5 + 0.16 comp cache 500 pages (asynchronous swap out)

real    22m7.306s
user    0m14.000s
sys     8m25.100s
 
pgpgin = 1149524
pgpgout = 1960240
pswpin = 127741
pswpout = 244950
 
compressed cache - statistics
-- algorithm --
WKdm
-- pages --
380752
-- size --
min        | max        | mean     
       272 |       3800 |         780
-- compression cycles --
min        | max        | mean
     24778 |   49622616 |       34641
-- decompression cycles --
min        | max        | mean
     11507 |   50171807 |       18755
		 
compression ratio:       19%
discarded pages:          5
discarded ratio:          0%

CVS as of Jul 3rd 2001: 2.4.5 + 0.16 comp cache + Hash Table


real    12m21.961s
user    0m18.100s
sys     1m13.800s

2.4.5 + 0.16 comp cache 500 pages (synchronous swap out)

 
real    29m47.271s
user    0m12.100s
sys     8m44.650s
 
pgpgin = 1038038
pgpgout = 1823374
pswpin = 113341
pswpout = 227831

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
358362
-- size --
min        | max        | mean     
       272 |       3800 |         779
-- compression cycles --
min        | max        | mean
     24662 |   66708828 |       36651
-- decompression cycles --
min        | max        | mean
     13820 |   26255679 |       19641
	 
compression ratio:       19%
discarded pages:          5
discarded ratio:          0%

2.4.5 vanilla

real    7m47.461s
user    0m26.800s
sys     0m55.050s

pgpgin = 1517694
pgpgout = 2860662
pswpin = 180396
pswpout = 357510

mmap002

1 time

command:
```
time ./mmap002 40
```

2.4.5 + 0.16 comp cache 500 pages (asynchronous swap out)

real    1m29.427s
user    0m2.650s
sys     0m15.050s
 
pgpgin = 158600
pgpgout = 219036
pswpin = 7614
pswpout = 7503

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
260
-- size --
min        | max        | mean     
       276 |       3800 |        1305
-- compression cycles --
min        | max        | mean
     26669 |     163452 |       36784
-- decompression cycles --
min        | max        | mean
     11927 |    1592535 |       29916
	 
compression ratio:       31% 
discarded pages:          5
discarded ratio:          1%

CVS as of Jul 3rd 2001: 2.4.5 + 0.16 comp cache + Hash Table


real    1m23.031s
user    0m4.100s
sys     0m9.950s

2.4.5 + 0.16 comp cache 500 pages (synchronous swap out)

real    1m58.013s
user    0m2.950s
sys     0m17.250s

pgpgin = 155170
pgpgout = 219242 
pswpin = 7525
pswpout = 7506

compressed cache - statistics
-- algorithm --
WKdm
-- pages --
271
-- size --
min        | max        | mean     
       276 |       3800 |        1295
-- compression cycles --
min        | max        | mean
     28409 |     223984 |       40227
-- decompression cycles --
min        | max        | mean
     16122 |    4959691 |       46286

compression ratio:       31%
discarded pages:          5
discarded ratio:          1%

2.4.5 vanilla

real    1m7.297s
user    0m4.150s
sys     0m8.600s

pgpgin = 157682
pgpgout = 222852
pswpin = 8023
pswpout = 8007

Page last updated on "Tue Jun 4 06:59:21 2002"
Send feedback to Rodrigo S. de Castro <rcastro@lists.sourceforge.net>