On Mon, 2007-05-07 at 10:44 -0700, Rick Jones wrote: > > Mostly I was thinking that not all PIO reads are the same "length" and so the > effect of the PIO read will vary, perhaps considerably, with the platform, > particularly for a very large NUMA platform. >
Oh I see. If the PIO read is "long" on the platform, the performance impact will be bigger. But it probably also means that it takes longer for the write to get to the chip to de-assert the IRQ. Without the read, it is therefore more likely to get an extra interrupt in such a case. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
