On Wed, 2025-06-11 at 18:32 +0300, Eero Tamminen wrote: > It will decrease performance if increased alignment means that something > that fit earlier into i/d-cache, does not fit any more.
»Control whether GCC aligns int, long, long long, float, double, and long double variables on a 32-bit boundary (-malign-int) or a 16-bit boundary (-mno-align-int). Aligning variables on 32-bit boundaries produces code that runs somewhat faster on processors with 32-bit busses at the expense of more memory.« Source: https://gcc.gnu.org/onlinedocs/gcc-3.1.1/gcc/M680x0-Options.html > (68030 has 256 bytes, 68040 has 4 KB, and 68060 has 8 KB, of both.) > > To get some numbers on this... > > if you could provide vmlinuz & System.map files for both (otherwise > identical) 2-byte & 4-byte alignment kernel builds, using kernel config > here: > https://github.com/hatari/hatari/blob/main/tools/linux/kernel.config > > I could measure the perf difference for the whole kernel boot, and if > there are differences, profile what causes those differences. But anyway, as I have said before, I am not going to change my mind on this and I'm already working on it. If you prefer maintaining a Linux port with 2 bytes alignment, you are free to do so. But please don't expect me to waste my time on it. Thanks, Adrian -- .''`. John Paul Adrian Glaubitz : :' : Debian Developer `. `' Physicist `- GPG: 62FF 8A75 84E0 2956 9546 0006 7426 3B37 F5B5 F913
