How frequently is the
proc file system updated on Linux? Is it 20 milliseconds (time quantum)?
The information that you read from the proc filesystem is not stored on any media (not even in RAM), so there is nothing to update.
The purpose of the proc file system is to allow userspace programs to obtain or set kernel data using the simple and familiar file system semantics (
The data that you see when you read from the proc filesystem is generated on-the-fly when you do a read from the begining of a file. That is, doing the read causes the data to be generated by a kernel callback function that is specific to the file you are reading. Doing an
The above is just a slightly more verbose way of saying what Hauke Laging states so succinctly. I suggest that you accept his answer.
It is updated on every access. You see the state of the kernel in that moment. That's why the size shown for the "files" is not the real size. The real size can change and is determined the moment you access the file.
You could say, it may be not updated for days. If you don't look at it. :-)