poor mm, vmstat -- flt/ fr peaks -- what does they mean?

[Marcin Koziej]

I use recent STABLE
I lately noticed some memory management related performance problems on 
my system -- I haven't changed the software I use (apart from upgrading 
some packages) but I get clicks/lags which playing music, which didn't 
happen before :( In fact, I've never had such 'lags' when clicking 
windows/firefox tabs or problems with music since FreeBSD 4.5.

I tried to trace this, but i don't have an idea how.
It seems there are peaks of faulting, and then freeing a lot of memory.
The music clicks are happening about 2-3 lines (seconds) below the peaks.

Also, there is a lot of 'fr' --freed pages, but the ammount of 'fre' - 
free pages does not change. what does this mean? It's not freeing 
because of forced swapping, because pi/po is 0 almost all the time

vmstat says:

  procs      memory      page                    disks     faults      cpu
  r b w     avm    fre  flt  re  pi  po  fr  sr ad0 cd0   in   sy  cs us 
sy id
  4 2 1  887924  76716 5678  10   3   3 6733 617   0   0 1154 11552 5400 
18 10 72
  0 2 1  887924  76708   71   1   0   0  52   0   0   0 1231 9366 5873 
12  6 82
  2 2 1  887924  76516  224   0   0   0 202   0   2   0 1245 29414 7338 
37  8 54
  2 2 1  887920  76512 13083   1   0   0 16187   0   0   0 1242 37314 
7983 38 22 40
  0 2 1  887920  76384  295   0   0   0 278   0   1   0 1275 56337 8235 
16 10 74
  0 3 0  887920  76384   72   0   0   0  65   0   0   0 1575 10924 6780 
  7  2 91
  1 2 1  887920  76384   40   0   0   0  50   0   0   0 1782 12263 7128 
  8  4 88
  1 2 1  887920  76384   69   0   0   0  65   0   0   0 1720 10189 7021 
17  4 78
  0 3 0  887920  76256 12732   0   0   0 15655   0   4   0 1225 9442 
5858 29 28 44
  0 2 1  887920  76256  155   0   0   0 157   0  18   0 1257 21274 6910 
11  6 83
  2 2 1  887920  76176  126   0   0   0 141   0   1   0 1248 22010 6824 
  6  4 90
  2 2 1  887924  76172   73   0   0   0  52   0   0   0 1755 10257 7042 
28  7 65
  1 2 1  887920  76048   42   0   0   0  51   0   1   0 1816 11311 7325 
28  4 67
  0 2 1  887936  76032 12804   0   0   0 15792   0   0   0 1797 10466 
7008 35 29 36
  1 3 0  887936  76028   46   0   0   0  67   0  14   0 1816 11688 7352 
  7  6 87
  0 3 0  887676  76416   70   0   0   0 162   0   0   0 1763 10971 7105 
13  7 80
  0 2 1  887680  76284   52   0   0   0  65   0   0   0 1727 52113 6806 
29 20 50
  1 3 0  887680  76284   69   0   0   0  50   0   1   0 1770 10418 7171 
19  7 73
  0 2 1  887688  76164 12804   0   0   0 15672   0  32   0 1763 12186 
6998 41 28 31
  1 2 1  887688  76164   69   0   0   0  65   0   0   0 1284 10588 6178 
  5  2 94
  1 2 1  887688  76036   44   0   0   0  52   0   1   0 1238 10377 5988 
  5  6 89
  0 2 1  887688  76036   71   0   0   0  65   0   0   0 1261 10256 5929 
14  4 82
  1 2 1  895776  70236 1845   0   0   0 136   0   1   0 1193 18138 5565 
34  8 57
  2 2 1  887688  76036 11269   0   0   0 15649   0   0   0 1288 10355 
5988 24 19 57
  1 2 1  887688  75796   75   0   0   0  79   0   2   0 1451 12141 6548 
  9  5 86
  2 2 1  887688  75796   69   0   0   0  65   0   0   0 1767 11031 7108 
  6  7 87
  1 2 1  887688  75812   40   0   0   0  69   0   1   0 1265 10258 5993 
18  5 77
(sorry for wrapped output)


Thank You for Your thoughts,

m.