[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH net-next v4 2/5] xen-netback: add support for IPv6 checksum offload from guest
On 14/10/13 11:55, Wei Liu wrote: > On Mon, Oct 14, 2013 at 11:49:20AM +0100, Paul Durrant wrote: >>> -----Original Message----- >>> From: Wei Liu [mailto:wei.liu2@xxxxxxxxxx] >>> Sent: 14 October 2013 11:43 >>> To: Paul Durrant >>> Cc: xen-devel@xxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; Wei Liu; David Vrabel; >>> Ian Campbell >>> Subject: Re: [PATCH net-next v4 2/5] xen-netback: add support for IPv6 >>> checksum offload from guest >>> >>> On Fri, Oct 11, 2013 at 04:06:19PM +0100, Paul Durrant wrote: >>> [...] >>>> -/* >>>> - * This is the amount of packet we copy rather than map, so that the >>>> - * guest can't fiddle with the contents of the headers while we do >>>> - * packet processing on them (netfilter, routing, etc). >>>> +/* This is a miniumum size for the linear area to avoid lots of >>>> + * calls to __pskb_pull_tail() as we set up checksum offsets. >>>> */ >>> >>> You seem to forget to explain why 128 is chosen. :-) >> >> Is that not sufficient explanation? What sort of thing are you looking for? >> > >>From the second version of this patch, we had a conversation. > >> Where does 128 come from? >> > > "It's just an arbitrary power of 2 that was chosen because it seems to > cover most likely v6 headers and all v4 headers." > > So something like: "We choose 128 which is likely to cover most V6 > headers and all V4 headers" would be sufficeint. Is "most IPv6 headers" actually good enough? Don't we need to ensure netback copies all IP headers? David _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
|
Lists.xenproject.org is hosted with RackSpace, monitoring our |