On 09/10/2014 01:33 PM, Johannes Berg wrote: > On Wed, 2014-09-10 at 16:06 -0400, Alexander Duyck wrote: >> The code for cloning the skb for an acknowledgement was checking to see if >> the cloned skb was shared and if it was it was then freeing the original >> skb. Since a clone should never really be shared I suspect that the >> intention was to avoid freeing the clone if the original was shared. As >> such I am updating the code so that if the original is shared we free the >> original and use the clone. This avoids unnecessary work in the next >> section where we would be cloning the skb if the original is shared. > > Thanks, yeah, I admit that this is clearly fishy. > >> @@ -2087,7 +2087,7 @@ netdev_tx_t ieee80211_subif_start_xmit(struct sk_buff >> *skb, >> if (id >= 0) { >> info_id = id; >> info_flags |= IEEE80211_TX_CTL_REQ_TX_STATUS; > > Luckily, we practically always go into this path. > >> - } else if (skb_shared(skb)) { >> + } else if (skb_shared(orig_skb)) { >> kfree_skb(orig_skb); >> } else { >> kfree_skb(skb); > > We have a clone already so we could just remove the whole "else if" I > think, but I'm guessing my intent was to keep it accounted to the socket > where possible rather than freeing the original in all cases. > > So yeah, I think this makes sense. Maybe we should add a comment to the > if though to explain this? > > johannes
Actually I think we may need to take a different approach. The reason I was in this code was to take a look at a possible refcount issue. I'll be submitting another patch in a few minutes and will probably be dropping some of this code anyway. Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html