From: Benjamin Herrenschmidt <[EMAIL PROTECTED]> Date: Thu, 22 Feb 2007 10:24:31 +1100
> The device has a single interrupt though that interrupt at least can > tell you which queues need servicing. It can't mask the interrupt per > queue though, which is the main issue. Right, which effectively turns it into a single interrupt for multiple queues as far as NAPI is concerned. > So while I think this scheme would work (the driver, ibm_emac, currently > uses a fake net_device and that sort-of works, budget is set a CONFIG_* > time though, I'm sure that can/needs to be improved), I've been > wondering all along if I could do something smarter by doing some > interrupt soft-disabling instead, though I have to get my head around > properly kicking softirqs from task context (if I need to re-trigger > from a enable_*() call occuring at task context). If you cannot make use of it sanely in your driver, it's hard to justify this patch just in the cleanup sense since it breaks NAPI interfaces and makes driver maintainence harder than it would need to be. Whereas if it makes a straightforward implementation in drivers like ibm_emac possible, this tends to tip things over the edge such that we can justify the maintainence hassles to some extent. I think the intention with these changes, is that you would have a napi struct per-queue. It would be embedded in some private per-queue software state struct, and from which you could also get to the device. So you'd do the "container_of()" bit a little bit differently at the beginning of your ->poll() method. This way you don't need the dummy netdevices. Anyways, please let us know what you come up with once you get a chance to investigate this. Thanks! - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
