On Sat, 2006-01-07 at 13:51 +0200, Thomas Graf wrote: > * jamal <[EMAIL PROTECTED]> 2006-06-30 22:23 > > I am not certain i understood then: Are we in the mode where the > > refcount is not needed because chances are small that a device will > > disappear? It seems to me after all this trouble that it may not be so > > bad to refcount (I guess i meant refcount the device on input to the ifb > > and decrement on the output). > > Based on two principles: > > a) All netdevices a packet is processed through is properly > refcounted until the packet is queued for the first time. > Given that iif is strictly set to the previous device, a > refcnt is certainly taken up to the point where the skb is > put into rq.
yes, but that refcount may be lost by the time it is dequeued and retransmitted. Am i wrong thinking so? > There is one exception to this: The fact that > you don't set skb->dev = ifb when reinjecting at ingress > will not take a refcnt on the ifb. This sounds like a broken > architecture to me but it doesn't matter as you want to > prohibit ifb -> ifb anyways. Ok, Thomas: Please stop critiqueing the architecture non-stop. You will not convince me of anything this way. Lets just focus on this issue and then you can go back and critique all you want. > > b) The netdevice used for xmit via dev_queue_xmit() is already > protected by the initial xmit attempt. > Is it guaranteed? if yes, the patch is perfect. > I can't see reason why to hurt performance by introducing more > atomic operations in your fast path. > well, i would be fine with this - with a caveat that nothing really has changed in ifb then, no? i.e the value of the patch in that case would be to convert input_dev to iif, correct? If yes, this is fine by me since as we have discussed the likelihood of this was small. > If you have more concerns regarding these patches, feel free to > fix your own architecture or propose to drop the patches, I think > I've spend enough time on this. Again, you are not being helpful by throwing in side remarks like these. I am being very fair to you when you ask questions on how X works after all assumptions you make - yet i ask questions which i see as valid and you start throwing your hands off in the air. And then Patrick says i am creating endless debates; this is why we go into loops. Just answer the questions: I am trying to understand or you can choose to ignore the emails all together. cheers, jamal - 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
