From: Ingo Molnar > Sent: 12 May 2019 10:32 ... > Has anyone investigated by any chance where the -ffreestanding space > savings come from mostly - is it mostly in cold paths, or does it make or > hot codepaths more efficient as well? > > If it's the latter then the kernel would be directly faster as well > (fewer instructions executed), not just indirectly from better cache > packing, I suppse?
My guess is that -ffreestanding stops gcc inlining memcpy() (etc). The calls can be smaller than the inline code, but will (probably) run more slowly. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)