On Thu, 25 Jan 2007 21:22:11 +0100 Svata Dedic <belgarat@xxxxxxxxxxxxxxx> wrote: > Hello, > > I am having troubles to set up network interfaces on our machine to > properly use SMP Linux features. There are two Broadcom Nextreme II > ethernet NICs onboard a 2x dual-core CPU machine. > > My kernel has SMP and Message-Signaled Interrupts (MSI) enabled. When I > boot with MSI enabled, I can see in /proc/interrupts that each of the > NICs got a unique interrupt assigned. But all traffic generated to the > 1st NIC goes to the CPU#0, other CPUs show 0 processed interrupts in the > /proc/interrupts. This is actually a designed beneficial state. If IRQ's happen on different CPU's then there is more cache memory thrashing and performance is lower. > I tried to assign the interrupt to a specific CPU (single bit in > smp_affinity, tried each of the 4 CPU cores), with the same results; > althought smp_affinity said e.g. 4, everything was processed by CPU#0 > > When the machine booted with "pci=nomsi" kernel parameter, the NICs were > assigned a shared IO-APIC interrupt, but the intr processing was > properly distributed among CPU cores as requested by the affinity_mask. > > What am I doing wrong ? > > Thanks for any advice, > -Svata > - > To unsubscribe from this list: send the line "unsubscribe linux-net" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Stephen Hemminger <shemminger@xxxxxxxxxxxxxxxxxxxx> - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
