From: Roland Dreier <[EMAIL PROTECTED]> Date: Tue, 30 Oct 2007 15:51:08 -0700
> In fact at least IBM pSeries boxes seem to be able to use MSI to > generate multiple interrupts from the same device -- BenH can probably > give details. Sparc64 PCI-E controllers can do this as well. > For high-performance devices this is not really true. The InfiniBand > mthca driver can use MSI to get a single interrupt, or MSI-X to get > different interrupts for different types of events. MSI-X allows the > read of the "interrupt cause register" to be avoided, and this ends up > making a measurable performance difference for the fast path. > > Also, obviously, having multiple interrupts means you can bind > different interrupts to different CPUs, which will become very > important if/when things like multi-queue NICs are supported. Right, and this is used heavily in the NIU driver for example. - 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/
