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Logging is very important at troubleshooting. However, it causes seriously slowing down when logging is so frequently and output device speed is limited. To avoid to slow down you can put logs to ring buffer on memory and flush it periodically. But if the target process suddenly abort by segmentation fault or some reason, the last log remaining the ring buffer may be lost. The last log is very important in troubleshooting.
My simple idea is to use file associated shared memory for the ring buffer. The key is to utilize mmap system call. In this session how the kernel handles mmap'ed memory is described. This talk targets developers who want to resolve problems in user space by logging. Knowledge in kernel inside is not required, but knowledge in system calls will be helpful.