Setting Affinities for Falcon Acceleration Cards Ports

To set affinities for Falcon Acceleration Cards ports, you use the standard Linux SMP IRQ Affinity mechanism.

On the Host appliance, you configure the applicable CPU Bitmasks in the /proc/irq/<IRQ_Number_of_Card_Port>/smp_affinity files for the IRQ numbers of the applicable Falcon Acceleration Cards ports.

The /proc/irq/<IRQ_Number_of_Card_Port>/smp_affinity files specify, which target CPU cores are permitted for a given IRQ source. These files hold bitmasks of allowed CPU cores.

Procedure:

1. Connect to the command line on the Host appliance.
2. Log in to Expert mode.
3. Get the list of slot numbers for the Falcon Acceleration Cards:

   fwaccel stat

4. Find the IRQ number for the Falcon Acceleration Card port, which you wish to affine to a specific CPU core:

   cat /proc/interrupts | grep msix | grep np<Slot#>

   Example for port np3:

   [Expert@FW:0]# cat /proc/interrupts | grep msix | grep np3   51: 9653025 0 0 0 0 6672298 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 PCI-MSI-X bcmnet-np3-msix-2   [Expert@FW:0]#

   Notes:

   • 51 - IRQ number of this Falcon Acceleration Card port
   • np3 - Falcon Acceleration Card port identifier
   • Compare with the output of the ifconfig eth<Slot#>-01 command
5. Find the CPU Bitmask in HEX Format of the CPU core, to which you wish to affine the specific Falcon Acceleration Card port:

   Note - This table addresses 24 CPU cores.

   CPU core	Bitmask in BIN Format	Bitmask in HEX Format
   CPU 0	00000001	1
   CPU 1	00000010	2
   CPU 2	00000100	4
   CPU 3	00001000	8
   CPU 4	00010000	10
   CPU 5	00100000	20
   CPU 6	01000000	40
   CPU 7	10000000	80
   CPU 8	01100100	100
   CPU 9	11001000	200
   CPU 10	000110010000	400
   CPU 11	001100100000	800
   CPU 12	001111101000	1000
   CPU 13	001111101000	2000
   CPU 14	111110100000	4000
   CPU 15	0001111101000000	8000
   CPU 16	0010011100010000	10000
   CPU 17	0100111000100000	20000
   CPU 18	1001110001000000	40000
   CPU 19	000000010011100010000000	80000
   CPU 20	000000011000011010100000	100000
   CPU 21	000000110000110101000000	200000
   CPU 22	000001100001101010000000	400000
   CPU 23	000011000011010100000000	800000

6. Write the applicable CPU Bitmask in HEX Format in the /proc/irq/<IRQ_Number_of_Card_Port>/smp_affinity file:

   echo <Hex_Bitmask> > /proc/irq/<IRQ_Number_of_Card_Port>/smp_affinity

   Examples:

   • Affinity of card port with IRQ 51 to CPU 0:

     echo 1 > /proc/irq/51/smp_affinity

   • Affinity of a card port with IRQ 59 to CPU 1:

     echo 2 > /proc/irq/59/smp_affinity

   • Affinity of card port with IRQ 234 to CPU 7:

     echo 80 > /proc/irq/234/smp_affinity

7. To make this configuration survive reboot, you need to add all these echo commands at the bottom of the /etc/rc.d/rc.local shell script:
   1. Create a backup copy of this shell script:

      cp -v /etc/rc.d/rc.local{,_BKP}

   2. Edit this shell script:

      vi /etc/rc.d/rc.local