Messages in this thread | | | Subject | Re: [PATCH V8 2/4 net-next] skbuff: skb supports zero-copy buffers | From | Shirley Ma <> | Date | Wed, 06 Jul 2011 16:24:14 -0700 |
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On Wed, 2011-07-06 at 17:01 -0600, Zan Lynx wrote: > On 7/6/2011 4:22 PM, Shirley Ma wrote: > > This patch adds userspace buffers support in skb shared info. A new > > struct skb_ubuf_info is needed to maintain the userspace buffers > > argument and index, a callback is used to notify userspace to > release > > the buffers once lower device has done DMA (Last reference to that > skb > > has gone). > > > > If there is any userspace apps to reference these userspace buffers, > > then these userspaces buffers will be copied into kernel. This way > we > > can prevent userspace apps from holding these userspace buffers too > long. > > > > Use destructor_arg to point to the userspace buffer info; a new tx > flags > > SKBTX_DEV_ZEROCOPY is added for zero-copy buffer check. > > > > Signed-off-by: Shirley Ma <xma@...ibm.com> > > I was just reading this patch and noticed that you check if > uarg->callback is set before calling it in skb_release_data, but you > do > not check before calling it in skb_copy_ubufs. > > I was only skimming so I have probably missed something...
It is a redundant check. The userspace buffer info always has a callback to release the buffers. I should have removed it after using tx_flags.
Thanks Shirley
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