What does "flush 253: 0" do in the iotop file on RHEL

Question

I track I / O performance on RHEL via IOTOP, and I find that there is one process called "flush 253: 0", which is the I / O statement itself.

What does this “253: 0 flash” mean? I am looking in google for a not very accurate answer, this seems to be the root path of the system.

Answer 1

This is a kernel process that processes the cleaning of dirty pages (i.e. your io-write) from the page cache (that is, your actual writes to the file system are asynchronous. This process writes the actual bytes to disks). See Also Cache and TLB Flushing Under Linux .