"While the internal buffer /proc/cpuinfo is read into is 32k is size, reading these 32k in a single chunk is not possible: Only up to a page worth of information is being returned in a single read (reading stops as soon as the full block for a subsequent CPU wouldn't fit into the buffer space remaining in the page anymore).

The effect is that only 5 or 6 CPUs (depending on the exact size info for one CPU has) get their frequency displayed (and the respective sensor offered for selection) on x86/x86-64 (where the page size is 4k).

Consequently, multiple reads (until zero bytes are read) must be issued to obtain all information."