Performance Improvements

SLUB -> Remove costly order
INT_SQRT function -> Update from mainline kernel and further optimized through inlining, register variables and code tweaking
KSM -> Use superior UKSM
RANDOM -> Use get_random_int() function to fix entropy depleting
READAHEAD -> Optimize get_next_ra_size function through shifts
                      -> Increase VM_MAX_READAHEAD to 512kB