I run a multi-process python program on CentOS. The program doesn't require a lot of memory. The wired thing is my 64GB memory machine is almost out of memory and have no ability to run other computationally intensive tasks. has anyone got the same problem? Updated:after sort processes by %MEM with part of the output like that:21922 haoyu     20   0 12.457g 1.204g      0 T   0.0  1.9   0:00.02 python21871 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.02 python21872 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.02 python21895 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.02 python21896 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.01 python21897 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.03 python21898 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.01 python21899 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.02 python21900 haoyu     20   0 12.433g 1.204g      0 T   0.0  1.9   0:00.01 pythonthe problem could be some mistakes in my multi-processes python program, looks the sub-processes hasn't been closed correctly and still take some memory. Since many of them are not currently active in using CPU, when applying top command without options I cannot see them.
unreasonable memory usage
centos;memory
On attached by you image you have processes/programs sorted by CPU usage not MEMory usage.Looks like python program you run uses ONLY 0.4% of memory (and 100% of CPU).Probably another process/program is using memory on your server.Please run command which will generates list of programs sorted by memory usage:top -o %MEM -b -n 1 | head -20and look at last column with name of process/program.It should give you an answer for question, What is using memory on your machine?.