Hello Heiner, Am Sonntag, den 26.10.2014, 19:05 +0100 schrieb Heiner Kallweit: > I use a mini pc with i.mx6 dual and Intel igb based nic (I211) connected via PCIE. > igb driver uses MSI-X and creates two rx/tx queue pairs. However the IRQs of all queues are handled by the same CPU. > Changing affinity is not possible. Obvious direct reason is that irq_chip PCI-MSI doesn't implement the callback > for setting cpu affinity. > I'd appreciate a hint whether this is a general limitation of the Cortex-A9 / GICv1 / Synopsys Designware > architecture or whether just a proper implementation is missing yet. > > Rgds, Heiner The MSI controller on imx6 doesn't support MSI-X so igb falls back to regular MSI interrupts. Also all MSI interrupts are aggregated into a single GIC interrupt line. This means the best we could do is switch all PCIe MSI interrupts to some other CPU. Configuring the CPU affinity on a per interrupt basis is impossible on this hardware. Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
