Peter P Waskiewicz Jr | a093bf0 | 2007-06-28 20:45:47 -0700 | [diff] [blame] | 1 | |
| 2 | HOWTO for multiqueue network device support |
| 3 | =========================================== |
| 4 | |
| 5 | Section 1: Base driver requirements for implementing multiqueue support |
Peter P Waskiewicz Jr | a093bf0 | 2007-06-28 20:45:47 -0700 | [diff] [blame] | 6 | |
| 7 | Intro: Kernel support for multiqueue devices |
| 8 | --------------------------------------------------------- |
| 9 | |
David S. Miller | b19fa1f | 2008-07-08 23:14:24 -0700 | [diff] [blame^] | 10 | Kernel support for multiqueue devices is always present. |
Peter P Waskiewicz Jr | a093bf0 | 2007-06-28 20:45:47 -0700 | [diff] [blame] | 11 | |
| 12 | Section 1: Base driver requirements for implementing multiqueue support |
| 13 | ----------------------------------------------------------------------- |
| 14 | |
| 15 | Base drivers are required to use the new alloc_etherdev_mq() or |
| 16 | alloc_netdev_mq() functions to allocate the subqueues for the device. The |
| 17 | underlying kernel API will take care of the allocation and deallocation of |
| 18 | the subqueue memory, as well as netdev configuration of where the queues |
| 19 | exist in memory. |
| 20 | |
| 21 | The base driver will also need to manage the queues as it does the global |
| 22 | netdev->queue_lock today. Therefore base drivers should use the |
| 23 | netif_{start|stop|wake}_subqueue() functions to manage each queue while the |
| 24 | device is still operational. netdev->queue_lock is still used when the device |
| 25 | comes online or when it's completely shut down (unregister_netdev(), etc.). |
| 26 | |
| 27 | Finally, the base driver should indicate that it is a multiqueue device. The |
| 28 | feature flag NETIF_F_MULTI_QUEUE should be added to the netdev->features |
| 29 | bitmap on device initialization. Below is an example from e1000: |
| 30 | |
| 31 | #ifdef CONFIG_E1000_MQ |
| 32 | if ( (adapter->hw.mac.type == e1000_82571) || |
| 33 | (adapter->hw.mac.type == e1000_82572) || |
| 34 | (adapter->hw.mac.type == e1000_80003es2lan)) |
| 35 | netdev->features |= NETIF_F_MULTI_QUEUE; |
| 36 | #endif |
| 37 | |
Peter P Waskiewicz Jr | a093bf0 | 2007-06-28 20:45:47 -0700 | [diff] [blame] | 38 | Author: Peter P. Waskiewicz Jr. <peter.p.waskiewicz.jr@intel.com> |