Messages in this thread | | | From | (bill davidsen) | Subject | Re: Can we kill f inb_p, outb_p and other random I/O on port 0x80, in 2.6? | Date | 23 Sep 2003 18:17:16 GMT |
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In article <20030922182808.GA28372@mail.jlokier.co.uk>, Jamie Lokier <jamie@shareable.org> wrote: | Arjan van de Ven wrote: | > The first person to complain about the extra branch miss in udelay for | > this will get laughed at by me ;) | | udelay(1) is too slow on a 386 even without the branch miss. | | If you think I/O operations are infinitely slower than other | instructions, please explain why there is asm-optimised I/O code in | asm-i386/floppy.h. | | :)
The choices are: 1 - there really were some old crappy chips which were both slow and timing sensitive 2 - someone thought that would optimize access 3 - gcc of the time generated bad code if you didn't
-- bill davidsen <davidsen@tmr.com> CTO, TMR Associates, Inc Doing interesting things with little computers since 1979. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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