On Mon, 17 Mar 2014 23:27:52 -0700 ebiederm@xxxxxxxxxxxx (Eric W. Biederman) wrote: > Add a test skb_irq_freeable to report when it is safe to free a skb > from irq context. > > It is not safe to free an skb from irq context when: > - The skb has a destructor as some skb destructors call local_bh_disable > or spin_lock_bh. > - There is xfrm state as __xfrm_state_destroy calls spin_lock_bh. > - There is netfilter conntrack state as destroy_conntrack calls > spin_lock_bh. > - If there is a refcounted dst entry on the skb, as __dst_free > calls spin_lock_bh. > - If there is a frag_list, which could be a list of any skbs. > Otherwise it appears safe to free a skb from interrupt context. > > - Update the warning in skb_releae_head_state to warn about freeing > skb's in the wrong context. > > - Update __dev_kfree_skb_irq to free all skbs that it can immediately > > - Kill zap_completion_queue because there is no point going through > a queue of packets that are not safe to free and looking for packets > that are safe to free. > > Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Why introduce the additional complexity for so little gain? It looks like you are only optimizing for the corner case where netpoll is cleaning up on Tx. -1 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html