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I am seeing memory usage, as reported by free creeping up with time, before eventually plateauing. Free reported 2,495Gb used, and 1,337Gb free. The summary in top seemed to concur with these values.
However if I add up the memory used by various process I cannot account for anywhere near that. Using ps_mem.pyhttp://www.pixelbeat.org/scripts/ps_mem.py , I can only account for 763Mb of RAM usage. I am taking the free memory value from the -/+ buffers/cache line, so this doesn't seem the widely encountered issue where people sometimes mistakenly read it from the first liine, which includes the buffering+caching:http://www.linuxatemyram.com/ This only seems to happen when I run Apache httpd on the server. I'm running a source build of Apache 2.4.3 on Redhat Enterprise Linux 6. Apache is only serving around one page a minute (as the server isn't in production usage yet). To see if the RAM reported as used by free, was actually available for use I used the "C munch program" at:http://www.linuxatemyram.com/play.html to attempt to allocate 3000Mb of memory, far more than free suggested was available, but what I thought should be available based upon the memory accounted for by ps_mem.py. This displaced some stuff into swap. But after the memory allocation program exited, free now reports much lower memory usage, which is far closer to what I would expect based upon ps_mem output Mem + swap before munch 2589 Mem + swap after munch 1184 If anyone can shed any light as to what's going on with the memory usage I would be very grateful. I have included the output of free, top (sorted by memory usage) and ps_mem.py below. Thanks, Paul free -m total used free shared buffers cached Mem: 3833 2896 937 0 282 118 -/+ buffers/cache: 2495 1337 Swap: 6142 94 6048 top - 09:02:54 up 7 days, 17:22, 1 user, load average: 0.07, 0.02, 0.00 Tasks: 125 total, 1 running, 124 sleeping, 0 stopped, 0 zombie Cpu(s): 1.0%us, 0.3%sy, 0.0%ni, 98.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 3925316k total, 2966540k used, 958776k free, 289028k buffers Swap: 6290424k total, 97100k used, 6193324k free, 121432k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 26523 sits_tom 20 0 1372m 209m 6244 S 0.0 5.5 2:00.14 java 26485 sits_tom 20 0 1372m 209m 6352 S 0.0 5.5 2:02.43 java 26568 sits_tom 20 0 1372m 201m 6248 S 0.0 5.2 1:58.63 java 1465 daemon 20 0 85092 41m 3460 S 0.0 1.1 19:15.98 .vasd 1600 daemon 20 0 73428 30m 5612 S 0.0 0.8 0:02.31 .vasd 1478 daemon 20 0 71312 28m 4164 S 0.0 0.7 41:37.49 .vasd 1479 daemon 20 0 88908 18m 5684 S 0.0 0.5 8:07.72 .vasd 5889 web_apac 20 0 1658m 17m 3864 S 1.0 0.5 12:50.66 httpd 1455 root 20 0 53060 9640 4892 S 0.0 0.2 1:02.75 .vasd 15010 root 20 0 806m 9484 3008 S 0.0 0.2 1:40.46 scxcimprovagt 14977 root 20 0 706m 5788 2948 S 0.0 0.1 1:28.11 scxcimserver 14845 root 20 0 110m 5784 4728 S 0.0 0.1 0:00.01 sshd 14878 root 20 0 184m 4492 3716 S 0.0 0.1 0:00.00 sudo 19308 postfix 20 0 87980 3736 2844 S 0.0 0.1 0:00.02 qmgr 14652 postfix 20 0 87800 3596 2748 S 0.0 0.1 0:00.00 pickup 15044 scom_msa 20 0 341m 3528 2956 S 0.0 0.1 0:06.22 scxcimprovagt 19293 root 20 0 78684 3300 2448 S 0.0 0.1 0:00.10 master 1319 root 20 0 249m 2668 800 S 0.0 0.1 0:01.44 rsyslogd 5879 root 20 0 122m 2536 2144 S 0.0 0.1 0:03.13 httpd 14850 s167 20 0 110m 2396 1320 S 0.0 0.1 0:00.01 sshd 14851 s167 20 0 121m 2276 1856 S 0.0 0.1 0:00.00 bash 14882 root 20 0 105m 2020 1548 S 0.0 0.1 0:00.01 bash ps_mem.py Private + Shared = RAM used Program 4.0 KiB + 39.5 KiB = 43.5 KiB rpc.idmapd 4.0 KiB + 40.5 KiB = 44.5 KiB acpid 4.0 KiB + 54.0 KiB = 58.0 KiB rpc.statd 0.0 KiB + 71.5 KiB = 71.5 KiB udevd (3) 60.0 KiB + 46.5 KiB = 106.5 KiB rpcbind 80.0 KiB + 60.0 KiB = 140.0 KiB rhsmcertd (2) 24.0 KiB + 123.0 KiB = 147.0 KiB mingetty (6) 184.0 KiB + 37.5 KiB = 221.5 KiB auditd 256.0 KiB + 81.5 KiB = 337.5 KiB init 296.0 KiB + 91.0 KiB = 387.0 KiB ntpd 368.0 KiB + 39.5 KiB = 407.5 KiB crond 296.0 KiB + 114.5 KiB = 410.5 KiB cronolog (5) 532.0 KiB + 211.5 KiB = 743.5 KiB catalina.sh (3) 876.0 KiB + 87.5 KiB = 963.5 KiB vmtoolsd 976.0 KiB + 421.5 KiB = 1.4 MiB master 1.0 MiB + 443.5 KiB = 1.4 MiB pickup 1.1 MiB + 446.5 KiB = 1.5 MiB qmgr 924.0 KiB + 685.5 KiB = 1.6 MiB bash (2) 1.3 MiB + 633.0 KiB = 1.9 MiB sudo 2.0 MiB + 59.5 KiB = 2.1 MiB rsyslogd 1.3 MiB + 2.1 MiB = 3.4 MiB sshd (3) 3.7 MiB + 494.0 KiB = 4.2 MiB scxcimserver 7.6 MiB + 1.4 MiB = 9.1 MiB scxcimprovagt (2) 14.2 MiB + 2.1 MiB = 16.4 MiB httpd (2) 105.2 MiB + 4.7 MiB = 109.9 MiB .vasd (5) 601.8 MiB + 5.0 MiB = 606.8 MiB java (3) --------------------------------- 763.6 MiB ================================= ### DURING MUNCH - 3000Mb allocated free -m total used free shared buffers cached Mem: 3833 3714 119 0 4 16 -/+ buffers/cache: 3694 139 Swap: 6142 508 5634 ### AFTER MUNCH free -m total used free shared buffers cached Mem: 3833 724 3108 0 5 16 -/+ buffers/cache: 703 3130 Swap: 6142 481 5661 top - 09:05:49 up 7 days, 17:25, 2 users, load average: 0.19, 0.08, 0.03 Tasks: 129 total, 1 running, 128 sleeping, 0 stopped, 0 zombie Cpu(s): 4.8%us, 0.0%sy, 0.0%ni, 95.2%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 3925316k total, 769064k used, 3156252k free, 9128k buffers Swap: 6290424k total, 490536k used, 5799888k free, 36352k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 26485 sits_tom 20 0 1372m 144m 4380 S 0.0 3.8 2:02.48 java 26568 sits_tom 20 0 1372m 61m 4328 S 0.0 1.6 1:58.69 java 26523 sits_tom 20 0 1372m 59m 4328 S 0.0 1.6 2:00.20 java 1465 daemon 20 0 85092 40m 2908 S 0.0 1.1 19:16.01 .vasd 1478 daemon 20 0 71312 25m 3104 S 0.0 0.7 41:37.55 .vasd 1600 daemon 20 0 73428 20m 3840 S 0.0 0.5 0:02.31 .vasd 1479 daemon 20 0 88908 12m 3832 S 0.0 0.3 8:07.79 .vasd 5889 web_apac 20 0 1658m 11m 3528 S 3.2 0.3 12:52.25 httpd 1455 root 20 0 53060 7696 3952 S 0.0 0.2 1:02.76 .vasd 15010 root 20 0 806m 7188 1696 S 0.0 0.2 1:40.49 scxcimprovagt 15108 root 20 0 110m 4616 4588 S 0.0 0.1 0:00.01 sshd 14845 root 20 0 110m 4592 4588 S 0.0 0.1 0:00.01 sshd 14878 root 20 0 184m 3664 3660 S 0.0 0.1 0:00.00 sudo 15141 root 20 0 184m 3660 3656 S 0.0 0.1 0:00.01 sudo 19308 postfix 20 0 87980 2796 2792 S 0.0 0.1 0:00.02 qmgr 14652 postfix 20 0 87800 2744 2684 S 0.0 0.1 0:00.00 pickup 19293 root 20 0 78684 2512 2432 S 0.0 0.1 0:00.10 master 5879 root 20 0 122m 2368 2084 S 0.0 0.1 0:03.14 httpd 1319 root 20 0 249m 2252 792 S 0.0 0.1 0:01.44 rsyslogd ps_mem.py Private + Shared = RAM used Program 4.0 KiB + 37.5 KiB = 41.5 KiB rpc.idmapd 4.0 KiB + 39.5 KiB = 43.5 KiB acpid 4.0 KiB + 40.0 KiB = 44.0 KiB rhsmcertd (2) 4.0 KiB + 51.0 KiB = 55.0 KiB rpc.statd 4.0 KiB + 68.5 KiB = 72.5 KiB udevd (3) 52.0 KiB + 41.5 KiB = 93.5 KiB rpcbind 24.0 KiB + 117.0 KiB = 141.0 KiB mingetty (6) 112.0 KiB + 38.5 KiB = 150.5 KiB crond 92.0 KiB + 81.0 KiB = 173.0 KiB ntpd 12.0 KiB + 163.5 KiB = 175.5 KiB catalina.sh (3) 176.0 KiB + 35.5 KiB = 211.5 KiB auditd 128.0 KiB + 94.5 KiB = 222.5 KiB cronolog (5) 160.0 KiB + 71.5 KiB = 231.5 KiB init 160.0 KiB + 389.5 KiB = 549.5 KiB pickup 180.0 KiB + 392.5 KiB = 572.5 KiB qmgr 204.0 KiB + 369.5 KiB = 573.5 KiB master 400.0 KiB + 233.0 KiB = 633.0 KiB scxcimserver 896.0 KiB + 74.5 KiB = 970.5 KiB vmtoolsd 508.0 KiB + 813.0 KiB = 1.3 MiB bash (4) 8.0 KiB + 1.4 MiB = 1.4 MiB sudo (2) 1.6 MiB + 56.5 KiB = 1.7 MiB rsyslogd 304.0 KiB + 2.5 MiB = 2.8 MiB sshd (5) 5.8 MiB + 579.0 KiB = 6.4 MiB scxcimprovagt (2) 8.3 MiB + 1.8 MiB = 10.1 MiB httpd (2) 88.6 MiB + 2.9 MiB = 91.5 MiB .vasd (5) 253.7 MiB + 3.2 MiB = 256.9 MiB java (3) --------------------------------- 376.8 MiB ================================= |
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