在启用交换功能的情况下对Android设备的性能进行基准测试（Swapon）

Question

What factors do I need to look at when benchmarking the performance of an android device with swap enabled? and what applications are recommended to use if there are any?

Enabling swap requires the phone to be rooted and it's kernel to support swap. "a-swapper" is one of the applications I use for enabling swap, basically it launches commands to enable swap. The swap file or swap partition is located at the external SD card.

Link to "a-swapper" at google code:

http://code.google.com/p/a-swapper/

Answer 1

Following is a report of my paging tests on a Raspberry Pi (ARM CPU, 512 MB RAM, SD drive). A test program writes and reads increasing volumes of data, checking for correct results and measuring speed in MB/second. Data sizes reported are 350, 400, 420 and 600 MB. Speed was at about one tenth max at 420 MB and three times slower at 600 MB. Links are included to obtain the benchmarks and C source code (FREE for anyone to play with and no Ads on any pages). As with my other benchmarks, this can be converted for Android.

http://www.roylongbottom.org.uk/Raspberry%20Pi%20Stress%20Tests.htm#anchor18

The report also provides vmstat monitoring of memory used, swapped, cache size, drive I/O and CPU utilisation. At least on my Android tablet, I can run vmstat via a Terminal Emulator at the same time as executing benchmarks.

For Windows and Linux, I have an image processing benchmark that increasingly enlarges images, with writing and reading to a drive, rotating and scrolling (You can find details by Googling for bmpspeed results.htm and Linux SDL Image Processing Benchmarks). If there is a suitable photo editor for Android, you can do the same with that using manual timing, and possibly monitor with vmstat.

Paging Test Results

StressInt uses normal memory writing and reading functions. Part 1 writes then reads the specified space with six passes using different data patterns. Reading is at high speed using AND and OR to produce a sumcheck. Part 2 writes the patterns (not timed) and reads them for at least a minimum time, in this case there is only one read pass for each pattern. The four paging tests specified 350, 400, 420 and 600 MB on a Raspberry Pi that has 512 MB RAM, with the main drive being an SD card. Vmstat was run at the same time.

At 350 MB, there is no swapping, but cache and buffer sizes are reduced, slowing down the first write pass. At 400 KB, swapping in and out at start then full speed when sorted. At 420 MB, chaos, continuous data transfer to and from the drive, CPU waiting for I/O.

1. Commands Example

 lxterminal -e ./stressInt KB 600000
 vmstat 10 > vmburn4.txt


 2. Results  
            MBytes Per Second At MB Data Size 

         MB        350    400    420    600    
 Write/Read No.
             1     139     24     15     14
             2     209    181     16      8 
             3     206    203     24      8
             4     206    204     26      8
             5     202    205     18      8
             6     206    205     20      8 

 Write/Rd secs    19.6   48.4  204.9  460.7

 Read       No.
             1     158    159     20      9
             2     158    159     14      9
             3     159    159     39      8
             4     160    155      9      9
             5     159    160     25      9
             6     160    159     10      9

 Total secs         85    125   1082   3085 

vmstat si so KB swaps in and out, bi bo KB I/O in and out, wa = waiting for I/O

350 MB vmstat 10 second samples

                 KBytes               KB       KB/sec    Per sec       %
procs  ----------memory---------- ---swap-- -----io---- -system-- ----cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs  us sy id wa
 0  0      0 314260  12340  56724    0    0    70     3 1123  232  19  5 76  0
 1  1      4   8920     48  21844    0    0    37    10 1141  298  42 16 42  0
 1  0      8  12392     64  18404    0    0     2     9 1161   89  99  1  0  0
 1  0      8  12144     80  18704    0    0    30     6 1167   82  99  1  0  0
 1  0      8  11896     88  18868    0    0    16     2 1157   71  99  1  0  0
 1  0      8  11764     96  18972    0    0    10     7 1163   71  99  1  0  0
 1  0      8  11772    104  18972    0    0     0     3 1152   61 100  0  0  0
 1  0      8  11772    112  18972    0    0     0     3 1153   65 100  0  0  0
 1  0      8  11772    120  18972    0    0     0     4 1154   68 100  0  0  0
 1  0      8  11772    128  18972    0    0     0     3 1153   64 100  0  0  0
 0  0      8 362344    136  21384    0    0   239     5 1194  294  22  4 73  1

400 MB 

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs  us sy id wa
 0  0      8 355220    924  26480    0    0    63     3 1125  236  24  4 72  0
 1  5  92368   8968     60   5464   10 9236   338  9245 1739  587  31 20 28 21
 0  2  52492   9108     44   5092 4775 3802  6938  3807 3429 1169  10 22  0 68
 1  2  71168  11236     44   4920 4654 8936  4929  8936 2428 1036   6 18  0 77
 1  1  42216   9224     44   4788 4477 5600  5059  5602 3313  992  37 19  0 45
 1  1  40948  11008     44   4932  143    0   591     3 1391  163  98  2  0  0
 1  0  40924  12248     60   5032   15    0    33     6 1170   87  98  2  0  0
 1  0  40912  12116     60   5228    2    0    21     0 1155   66  99  1  0  0
 1  0  40912  12000     68   5228    0    0     0     3 1152   58 100  1  0  0
 1  0  40912  12000     76   5260    3    0     6     3 1154   60 100  1  0  0
 1  0  40892  12000     84   5260    0    0     0     3 1153   63  99  1  0  0
 1  0  40704  11628     92   5260   34    0    34     3 1167   69 100  1  0  0
 1  0  40700  11628    100   5260    0    0     0     3 1153   61 100  0  0  0
 0  0  37956 401996    236  12804  474    0  1208     0 1626  229  89  5  3  3
 0  0  36900 400392    244  13372  103    0   160     7 1125  180   6  2 91  1

420 MB Sample

procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs  us sy id wa
 0  3  59316   8820     48   4212 4238 4269  5132  4272 3592  939  20 16  0 65
 0  1  68268  11732     44   3400 4281 5112  4736  5114 3337  938   6 19  0 75
 1  3  60804   8820     76   4428 4715 3860  5877  3864 3518 1007  13 17  0 70
 1  1  56408   9948     44   2976 4710 4164  6948  4168 4389 1186   5 19  0 75
 2  2  70864  11704     44   2068 3975 6458  4908  6461 3854 1021   7 14  0 79

Following are results on 64 bit Windows systems, essentially from same C code as on Raspberry Pi but using one write/read pass. For these tests the benchmark was run with increasing data demands up to 5, 8 and 14 GB on the three systems.

          64 Bit IntBurn64         64 Bit IntBurn64         64 Bit IntBurn64

      CPU     Athlon 64               Core 2 Duo                 Phenom II
      MHz       2210                     2400                       3000
   RAM MB       1024                     4096                       8192
  Windows      XP x64               64-Bit Vista             64-Bit Windows 7
 Disk W/R
   MB/sec         55                       55                         92

         KB    Secs  MB/sec         KB    Secs  MB/sec         KB    Secs  MB/sec

     100000            2041     100000            3393     100000            5146

     800000       1    1976    2500000       2    2868    2000000       1    4900
     850000      23      77    3000000       2    2878    3000000       1    4658
     900000      58      32    3100000       2    2847    3500000       2    4651
     920000      61      31    3200000       2    2899    4000000       2    4488
     930000      91      21    3300000       3    2698    4500000       2    4489
     940000      96      20    3400000       3    2610    5000000       2    4477
     950000      93      21    3500000       7    1075    5500000       3    4166
     960000      89      22    3600000      10     750    6000000       3    4051
     970000     142      14    3700000      17     459    6500000       3    4036
     980000     125      16    3800000     107      73    7000000       4    4078
     990000     119      17    3900000     210      38    7500000      72     214
    1000000     128      16    4000000     146      56    7600000     170      91
    1100000     188      12                               7700000     168      94
    1200000     205      12    5000000    1024      10    7800000     230      69
    1300000     266      10    7000000     652      22    7900000     239      68
    1400000     358       8    7900000     770      21    8000000     227      72
                               8000000             N/A    9000000     697      26
    2000000     683       6                              10000000    1231      17
    2100000                                              14000000    2742      10
    5000000    1707       6                              15000000             N/A

BMPSpeed Benchmark generates BMP files up to 512 MB. It measures speed of saving, loading, scrolling, rotating and editing/enlarging of 0.5, 1, 2, 4 etc. MB files upwards. Memory used is up to 2.5 times image size. The original had to be modifies for a Windows XP as 1.25 GB of sequential memory space could not be allocated. The first example below reflects paging at 256 MB but some memory would be cleared for a rerun. A second problem arises on later systems, with more graphics RAM, where fast BitBlt copying can be used at larger image sizes and this requires far more space than the slower StretchDIBits method.

I might produce a new 64 bit version to see if I can bust my new benchmarking toy with 32 GB RAM.

    BMPSpeed Results

    2.08 GHz CPU, 512 MB RAM, fast disk, slow GeForce graphics

   Input Enlarge    Save    Load  Scroll  Scroll  Rotate     Use
   Image Display         Display /Repeat Overall  90 deg    Fast
  Mbytes    Secs    Secs    Secs   msecs  MB/Sec    Secs  BitBlt

     0.5    0.05    0.01    0.03     0.7   992.8    0.04      3
     1.0    0.06    0.02    0.05     1.3  1013.2    0.06      3
     2.0    0.08    0.03    0.12     2.3  1019.8    0.09      3
     4.0    0.11    0.06    0.17     2.9  1032.4    0.15      3
     8.0    0.15    0.14    0.43    11.4   262.7    0.25      3
    16.0    0.24    0.29    0.51    11.4   262.7    0.81      3
    32.0    0.45    0.61    0.88    11.4   262.5    1.10      3
    64.0    0.55    1.31    1.49    41.4    72.2    2.79      0
   128.0    0.97    2.50    2.83    53.9    55.5    6.21      0
   256.0   73.02   88.77   14.84   109.7    27.3   86.60      0
   512.0   82.93   20.70   89.05   842.4     3.5   67.98      0


 2.4 GHz Core 2 Duo with 4 GB RAM and 64 Bit Vista, fast GeForce

   Input Enlarge    Save    Load  Scroll  Scroll  Rotate     Use
   Image Display         Display /Repeat Overall  90 deg    Fast
  Mbytes    Secs    Secs    Secs   msecs  MB/Sec    Secs  BitBlt

     0.5    0.05    0.01    0.05     0.1  4748.4    0.02      3
     1.0    0.05    0.02    0.08     0.3  4463.6    0.03      3
     2.0    0.07    0.02    0.11     1.1  2475.2    0.04      3
     4.0    0.09    0.03    0.19     2.4  1866.0    0.06      3
     8.0    0.13    0.08    0.31     2.9  1765.0    0.10      3
    16.0    0.20    0.24    0.48     2.7  1832.5    0.17      3
    32.0    0.26    0.52    0.78     2.9  1741.2    0.28      3
    64.0    0.39    1.08    1.38     2.9  1760.0    0.52      3
   128.0    0.68    2.37    2.63     2.9  1740.3    1.03      3
   256.0    1.35    4.62    5.38     3.1  1645.6    4.39      3
   512.0   27.91   13.05   10.59     3.2  1595.6   57.11      3