Strange Swapping Issues(?)

[Gabor PALI]

Hello,

On 04/15/10 20:41, Peter Jeremy wrote:
> The out-of-swap hander will kill the largest process so one of your
> problems is probably "throwto003".  I can't offer any suggestion as
> to why the swap_pager_getswapspace() errors continued afterwards.

Okay, it was my fault.  After huge processes, like "throwto003" are
killed, swap usage falls below 3-4% in a second.  (I will need to
consult the author of that processes.)

For your amusement, here is a log excerpt of the situation (it can by
easily reproduced on my system).

Columns are as follows:

- Time
- Swap Used (KB) [swapinfo]
- Swap Free (KB) [swapinfo]
- Number of Processes [ps]
- Active Virtual Pages (KB) [vmstat]
- Size of Free List (KB) [vmstat]


Messages are pounding the logs at 17:16:37:  "kernel:
swap_pager_getswapspace(12): failed", and at 17:16:39 "throwto003" is
finally killed:  "kernel: pid 117 (throwto003), uid 1001, was killed:
out of swap space", no further fails.


17:15:30        81720   4112584 155     2033636 71464
17:15:31        81720   4112584 155     2777084 9732
17:15:41        439384  3754920 155     2953212 10104
17:15:42        493804  3700500 155     3121148 10152
17:15:44        730560  3463744 155     3280812 10208
17:15:47        817608  3376696 155     3459068 9980
17:15:49        988420  3205884 155     3625008 10268
17:15:51        1182748 3011556 155     3799036 10036
17:15:53        1326872 2867432 155     3963900 8280
17:15:54        1445332 2748972 155     3969020 9632
17:15:55        1457348 2736956 155     4093928 40304
17:15:57        1598944 2595360 155     4139004 10568
17:15:58        1646460 2547844 155     4276220 8360
17:15:59        1689776 2504528 155     4365308 8476
17:16:00        1882924 2311380 155     4453372 89048
17:16:04        2049676 2144628 155     4567036 9860
17:16:06        2219004 1975300 155     4733948 10264
17:16:08        2389028 1805276 155     4903932 10012
17:16:10        2558516 1635788 155     5047396 99916
17:16:12        2735864 1458440 157     5254428 10532
17:16:15        2917096 1277208 158     5475788 100944
17:16:17        3103632 1090672 159     5716856 98876
17:16:20        3231660 962644  159     5929908 40144
17:16:24        3498256 696048  159     6168504 68192
17:16:28        3675324 518980  159     6238136 10700
17:16:30        3861972 332332  159     6414172 8500
17:16:32        4032132 162172  157     6556588 10324
17:16:33        4054828 139476  155     6718460 7932
17:16:34        4176548 17756   155     6719536 9584
17:16:38        4193604 700     155     6799908 71096
17:16:39        100580  4093724 151     1132240 1640856
17:16:40        96336   4097968 151     1123620 1637372
17:16:41        96332   4097972 153     1189608 1613748
17:16:42        96328   4097976 156     1269164 1529760
17:16:43        96272   4098032 154     1147628 1602084


Cheers,
:g