Re: Information about napi_struct and net_device

On Sat, 2012-10-27 at 18:18 +0200, Javier Domingo wrote:

Hello,

I am updating a kernel patch from 2.6.23-rc7 to v3.6, using git
facilities, and I have found that there have been lots of changes in
networking. Now the drivers are all by vendor, and more important,
net_device is not used always, as napi_struct took its place.

Yes, some directories were created and files moved around.

Not really a big deal (no real code change)

I have asked in #kernel but no one answered me, so I subscribed here.
Is there any place I can read about how is it now designed the use of
napi_struct and net_device? I have found a presentation[1] about how
networking was changing etc, and I wondered if there is anything more
precise about how it is actually implemented.

I understand a little why napi_struct, but don't really know much
about the change,

Hope someone can help me,

Seems quite straightforward, we probably should add some docs in 
Documentation/networking/netdevices.txt

You could take a look at a small driver like
drivers/net/ethernet/realtek/8139cp.c

and grep for "napi" in it


# grep -n napi drivers/net/ethernet/realtek/8139cp.c
327:	struct napi_struct	napi;
436:	napi_gro_receive(&cp->napi, skb);
468:static int cp_rx_poll(struct napi_struct *napi, int budget)
470:	struct cp_private *cp = container_of(napi, struct cp_private, napi);
566:		napi_gro_flush(napi, false);
568:		__napi_complete(napi);
605:		if (napi_schedule_prep(&cp->napi)) {
607:			__napi_schedule(&cp->napi);
1132:	napi_enable(&cp->napi);
1149:	napi_disable(&cp->napi);
1160:	napi_disable(&cp->napi);
1933:	netif_napi_add(dev, &cp->napi, cp_rx_poll, 16);