Hello, dear all,
I met a strange issue, where I can not find the root cause.
Serveral days agao, the free memory was only 9M left. Now, the free
memory came back to 120M.
>From the top log, all the process memory usage was no big change, and
also cache and buffers.

I paste these two times top log, I hope someone can help me figure it
out.

Environment: linux kernel 2.4
--------------------------------------------------------------------------------------------------------
Serveral Days Ago:

23:37:54 up 122 days, 22:13, 1 user, load average: 0.00, 0.01, 0.00
178 processes: 171 sleeping, 7 running, 0 zombie, 0 stopped
CPU states: 1.3% user 1.2% system 0.4% nice 0.0% iowait 96.8%
idle
Mem: 1001920k av, 992124k used, 9796k free, 0k shrd,
3488k buff
682876k active, 82332k inactive
Swap: 0k av, 0k used, 0k free
596180k cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU
COMMAND
625 root 9 0 3272 3272 2172 S 6.4 0.3 1245m 0
SpHwmCpm_cpmon
8851 root 16 0 1088 1088 760 R 6.4 0.1 0:00 0 top
533 root 10 0 2636 2636 2008 S 0.9 0.2 215:15 0 elm
652 root 9 0 2196 2196 1500 S 0.9 0.2 210:23 0 mwp
659 root 9 0 7780 7780 7736 S 0.9 0.7 496:08 0
megaco_mgc
1 root 8 0 492 492 436 S 0.0 0.0 0:04 0 init
2 root 9 0 0 0 0 SW 0.0 0.0 0:00 0
keventd
3 root 18 19 0 0 0 SWN 0.0 0.0 0:00 0
ksoftirqd_CPU0
4 root 9 0 0 0 0 SW 0.0 0.0 0:00 0
kswapd
5 root 9 0 0 0 0 SW 0.0 0.0 0:00 0
bdflush
6 root 9 0 0 0 0 SW 0.0 0.0 0:00 0
kupdated
250 root 9 0 656 652 556 S 0.0 0.0 0:00 0
syslogd
258 root 9 0 520 520 388 S 0.0 0.0 0:00 0
klogd
264 root 9 0 552 552 484 S 0.0 0.0 0:00 0
inetd
267 root 9 0 640 640 544 S 0.0 0.0 0:00 0 cron
306 root 9 0 1056 1052 876 S 0.0 0.1 0:55 0
S74ntpd
480 root 9 0 3312 3312 2040 S 0.0 0.3 0:00 0
SeAppMgr
489 root 9 0 1772 1772 1336 S 0.0 0.1 0:33 0
SeNodeMgr
499 root 9 0 1408 1408 1072 S 0.0 0.1 0:00 0
FileUpldr
503 root 9 0 1596 1596 1240 S 0.0 0.1 63:34 0
SeComMgr
508 root 9 0 1348 1348 1040 S 0.0 0.1 0:00 0
SeFwdMgr
512 root 9 0 1700 1700 1172 S 0.0 0.1 0:00 0
SeEventMgr
517 root 9 0 1912 1912 1748 S 0.0 0.1 0:00 0 ntpd
522 root 10 0 1060 1056 880 S 0.0 0.1 0:00 0
S99ChkIdmFreeSp
523 root 9 0 428 428 376 S 0.0 0.0 0:00 0
getty
529 root 9 0 2608 2608 1904 S 0.0 0.2 0:01 0
SpHwmFtm_fiso
538 root 9 0 1432 1432 1124 S 0.0 0.1 0:00 0
DaemonMonitor
563 root 9 0 36172 35M 34100 S 0.0 3.6 1:18 0
rtdbLS
571 root 9 0 1764 1764 1508 S 0.0 0.1 0:00 0
IDM_MonitorMgr
573 root 9 0 1876 1876 1600 S 0.0 0.1 0:00 0
IDM_Monitor
575 root 9 0 2208 2208 1916 S 0.0 0.2 0:00 0
IDM_TransportRe
577 root 9 0 2012 2012 1732 S 0.0 0.2 0:00 0
IDM_TransportSe
579 root 11 1 293M 293M 291M S N 0.0 30.0 0:39 0
IDM_Distributor
581 root 9 0 2060 2060 1764 S 0.0 0.2 0:00 0
IDM_LogRecovery
583 root 9 0 140M 140M 140M S 0.0 14.4 0:00 0
IDM_LogRecovery
585 root 9 0 2016 2016 1720 R 0.0 0.2 0:00 0
IDM_Transaction
587 root 9 0 2252 2252 1964 R 0.0 0.2 0:00 0
IDM_Transaction
620 root 9 0 2768 2768 1956 S 0.0 0.2 0:00 0
SpHwmCfm_config
629 root 9 0 2376 2376 1784 S 0.0 0.2 0:00 0
SpOkm_Kernel_mg
634 root 9 0 18680 18M 17932 S 0.0 1.8 1:47 0
TmmLdcMain
645 root 9 0 2156 2156 1580 S 0.0 0.2 0:00 0
mwdir
660 root 9 0 210M 210M 69788 S 0.0 21.4 2640m 0
CmaCoCo
718 root 9 0 1536 1536 1132 S 0.0 0.1 0:00 0
scanMgcp
8694 root 9 0 848 848 700 S 0.0 0.0 0:00 0
in.rlogind
8695 root 9 0 1448 1448 1036 S 0.0 0.1 0:00 0 bash
8849 root 9 0 480 480 416 S 0.0 0.0 0:00 0
sleep
8856 root 10 0 480 480 416 S 0.0 0.0 0:00 0
sleep


--------------------------------------------------------------------------------------------------------
Today:

14:00:56 up 133 days, 12:35, 2 users, load average: 0.02, 0.06,
0.04
180 processes: 179 sleeping, 1 running, 0 zombie, 0 stopped
CPU states: 1.3% user 1.2% system 0.4% nice 0.0% iowait 96.9%
idle
Mem: 1001920k av, 880952k used, 120968k free, 0k shrd,
3528k buff
685116k active, 81208k inactive
Swap: 0k av, 0k used, 0k free
596656k cached

PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU
COMMAND
15241 root 18 0 1116 1116 760 R 6.3 0.1 0:00 0 top
660 root 9 0 211M 211M 71276 S 1.8 21.6 2844m 0
CmaCoCo
659 root 9 0 7780 7780 7736 S 0.9 0.7 534:06 0
megaco_mgc
1 root 8 0 492 492 436 S 0.0 0.0 0:04 0 init
2 root 9 0 0 0 0 SW 0.0 0.0 0:00 0
keventd
3 root 18 19 0 0 0 SWN 0.0 0.0 0:00 0
ksoftirqd_CPU0
4 root 9 0 0 0 0 SW 0.0 0.0 0:01 0
kswapd
5 root 9 0 0 0 0 SW 0.0 0.0 0:00 0
bdflush
6 root 9 0 0 0 0 SW 0.0 0.0 0:00 0
kupdated
250 root 9 0 656 652 556 S 0.0 0.0 0:00 0
syslogd
258 root 9 0 520 520 388 S 0.0 0.0 0:00 0
klogd
264 root 9 0 552 552 484 S 0.0 0.0 0:00 0
inetd
267 root 9 0 640 640 544 S 0.0 0.0 0:00 0 cron
306 root 9 0 1056 1052 876 S 0.0 0.1 0:58 0
S74ntpd
480 root 9 0 3312 3312 2040 S 0.0 0.3 0:00 0
SeAppMgr
489 root 9 0 1772 1772 1336 S 0.0 0.1 0:36 0
SeNodeMgr
499 root 9 0 1408 1408 1072 S 0.0 0.1 0:00 0
FileUpldr
503 root 9 0 1596 1596 1240 S 0.0 0.1 68:24 0
SeComMgr
508 root 9 0 1348 1348 1040 S 0.0 0.1 0:00 0
SeFwdMgr
512 root 9 0 1700 1700 1172 S 0.0 0.1 0:00 0
SeEventMgr
517 root 9 0 1912 1912 1748 S 0.0 0.1 0:00 0 ntpd
522 root 9 0 1060 1056 880 S 0.0 0.1 0:00 0
S99ChkIdmFreeSp
523 root 9 0 428 428 376 S 0.0 0.0 0:00 0
getty
529 root 9 0 2608 2608 1904 S 0.0 0.2 0:01 0
SpHwmFtm_fiso
533 root 9 0 2636 2636 2008 S 0.0 0.2 234:58 0 elm
538 root 9 0 1432 1432 1124 S 0.0 0.1 0:00 0
DaemonMonitor
563 root 9 0 36484 35M 34412 S 0.0 3.6 1:24 0
rtdbLS
571 root 9 0 1764 1764 1508 S 0.0 0.1 0:00 0
IDM_MonitorMgr
573 root 9 0 1876 1876 1600 S 0.0 0.1 0:00 0
IDM_Monitor
575 root 9 0 2208 2208 1916 S 0.0 0.2 0:00 0
IDM_TransportRe
577 root 9 0 2052 2052 1772 S 0.0 0.2 0:00 0
IDM_TransportSe
579 root 11 1 293M 293M 291M S N 0.0 30.0 0:42 0
IDM_Distributor
581 root 9 0 2060 2060 1764 S 0.0 0.2 0:00 0
IDM_LogRecovery
583 root 9 0 140M 140M 140M S 0.0 14.4 0:00 0
IDM_LogRecovery
585 root 9 0 2016 2016 1720 S 0.0 0.2 0:00 0
IDM_Transaction
587 root 9 0 2292 2292 2004 S 0.0 0.2 0:00 0
IDM_Transaction
620 root 9 0 2768 2768 1956 S 0.0 0.2 0:00 0
SpHwmCfm_config
625 root 9 0 3272 3272 2172 S 0.0 0.3 1354m 0
SpHwmCpm_cpmon
629 root 9 0 2376 2376 1784 S 0.0 0.2 0:00 0
SpOkm_Kernel_mg
634 root 9 0 18680 18M 17932 S 0.0 1.8 1:54 0
TmmLdcMain
645 root 9 0 2156 2156 1580 S 0.0 0.2 0:00 0
mwdir
652 root 9 0 2196 2196 1500 S 0.0 0.2 227:59 0 mwp
718 root 9 0 1536 1536 1132 S 0.0 0.1 0:00 0
scanMgcp
14724 root 9 0 848 848 700 S 0.0 0.0 0:00 0
in.rlogind
14725 root 9 0 1460 1460 1036 S 0.0 0.1 0:00 0 bash
15105 root 9 0 848 848 700 S 0.0 0.0 0:00 0
in.rlogind
15106 root 10 0 1448 1448 1036 S 0.0 0.1 0:00 0 bash
15233 root 9 0 480 480 416 S 0.0 0.0 0:00 0
sleep
15240 root 9 0 480 480 416 S 0.0 0.0 0:00 0 sleep