Hello, I have a small system:
- 6GB drive - ext4 partition mounted readonly - swap partition that is not listed in fstab and not enabled. (I will swapon it every few weeks or so if I need it for a large compile job) - 2 GB RAM When the system boots it processing video from a USB camera. The program dynamically allocates and releases memory while it runs, but stores no data in memory or on disk (read-only). The memory usage does not grow over time. When things are going well, top looks like so: === Tasks: 68 total, 1 running, 67 sleeping, 0 stopped, 0 zombie %Cpu0 : 88.3 us, 11.7 sy, 0.0 ni, 0.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu1 : 25.5 us, 2.3 sy, 0.0 ni, 72.1 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu2 : 6.0 us, 0.7 sy, 0.0 ni, 93.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st %Cpu3 : 25.7 us, 2.3 sy, 0.0 ni, 72.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st KiB Mem: 1861644 total, 161648 used, 1699996 free, 6948 buffers KiB Swap: 0 total, 0 used, 0 free, 57728 cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2129 root 20 0 1774440 81712 25388 S 160.0 4.4 25:55.46 obt 705 root 20 0 0 0 0 S 1.0 0.0 0:07.87 kswapd0 2049 ueyed 20 0 620472 14092 13652 S 1.0 0.8 0:09.34 ueyeusbd ==== Q1: Why does the kswapd0 process from time to time take up 100% CPU? Q2: Why does top show "cached swap" eventhough I do not have swap mounted? Q3: Is there anything I can do to prevent kswapd0 from using CPU on my system? e.g. disable SWAP in the kernel config I suspect the answer to Q1 is: a) kernel is not configured properly for my hardware or b) there is some bad side effect to my readonly root fs Thank you, Chris
