On Fri, Dec 06, 2002 at 06:18:22PM +0000, Dominic Sweetman wrote: > > The first kernel was built as 64-bit ELF using 64-bit pointer and everything > > 64-bit. The second kernel was built using the -Wa,-32 trick. That's over > > 12% of bloat for full 64-bitiness which brings zero gain. > > Percentages are dangerous things. This is 220Kbytes of memory, which > currently represents an investment of about $0.05. There may be > embedded linux applications which care about 5c cost, but they > probably won't use any variety of 64 bits... I'd worry less if that was just 220kB of unused memory wasted. But it's actually inflated code, it's wasted i-cache and cycles. 220kB translates to alost 7 times the size of today's typical 32kB i-cache. Even if Thiemo was right this trick is probably the biggest micro- optimization of the decade ... Ralf
