brw_read in llite client procfs stats file claims to measure in units of pages. For example:
However, in ./lustre/llite/lloop.c the tallying of the LPROC_LL_BRW_WRITE/READ counter increments by the value of:
Using this value has the effect of not measure pages, but the total bytes of the pages. A simple fix maybe to remove the PAGE_CACHE_SHIFT. Or, rename '[pages]' to '[bytes]' in the output.