>-----Original Message----- >From: David Miller [mailto:davem@xxxxxxxxxxxxx] >Sent: Thursday, November 11, 2010 1:47 AM >To: Xin, Xiaohui >Cc: netdev@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; >mst@xxxxxxxxxx; mingo@xxxxxxx; herbert@xxxxxxxxxxxxxxxxxxx; jdike@xxxxxxxxxxxxxxx >Subject: Re: [PATCH v15 00/17] Provide a zero-copy method on KVM virtio-net. > >From: xiaohui.xin@xxxxxxxxx >Date: Wed, 10 Nov 2010 17:23:28 +0800 > >> From: Xin Xiaohui <xiaohui.xin@xxxxxxxxx> >> >>>2) The idea to key off of skb->dev in skb_release_data() is >>> fundamentally flawed since many actions can change skb->dev on you, >>> which will end up causing a leak of your external data areas. >> >> How about this one? If the destructor_arg is not a good candidate, >> then I have to add an apparent field in shinfo. > >If destructor_arg is actually a net_device pointer or similar, >you will need to take a reference count on it or similar. > Do you mean destructor_arg will be consumed by other user? If that case, may I add a new structure member in shinfo? Thus only zero-copy will use it, and no need for the reference count. >Which means --> good bye performance especially on SMP. > >You're going to be adding new serialization points and at >least two new atomics per packet. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
