On Tue, 1 Jan 2008 17:43:38 +0100 Ingo Molnar <[EMAIL PROTECTED]> wrote:
> if someone runs a fresh new kernel on an ancient device then timings > _will_ change a bit, no matter what we do. Alignments change, the > compiler output will change (old compilers get deprecated so a new > compiler might have to be picked), cache effects change - and this is > inevitable. The important thing is to not eliminate the delays - but > we sure dont have to keep them cycle accurate (we couldnt even if we > wanted to). The only way to get the _exact same_ behavior is to not > change the kernel at all. What I'm afraid is that udelay will be significantly slower, which might hit anything that does a lot of gettimeofday calls (poking at the PIT timer) on embedded 386/486 systems. On the other hand, those systems might not want to upgrade to 2.6 anyway. And why do people keep buying HP hardware? HP seem to be quite Linux-unfriendly on the desktop [1] and on their laptops. Apparently HP doesn't even bother to try Linux on any of their non-server systems. [1] Try running Linux on a HP DC7700 machine, there seems to be a lot of magic stuff in those machines that doesn't work well with Linux. They had some ACPI crap that stopped FC7 from booting without a lot of magic PCI access options and audio still does not work. /Christer -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
