On Wed, 14 Feb 2007 13:53:08 -0800 Zachary Amsden <[EMAIL PROTECTED]> wrote:
> > IDE on several platforms has performance critical paths that use > > ndelay(400) or failing that udelay(1) > > Ok, I buy that. A 486DX / 33 Mhz processor takes 10 cycles to issue a > CALL / RET pair. This is about 300ns. Is there an issue with being too > early to issue I/O operations or too late? Too early you lose, too late you just waste clock time. > But I fail to see how such careful timing can be done at this > granularity on such hardware without well tweaked assembly code. Thats what is used most platforms use udelay(1) in fact however - 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/