Messages in this thread | | | Subject | Re: [PATCH V3 2/8] Add a new zerocopy device flag | From | Shirley Ma <> | Date | Tue, 03 May 2011 13:11:21 -0700 |
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On Tue, 2011-05-03 at 10:42 -0700, Shirley Ma wrote: > Better to prevent this kind of skbs to be used in skb_clone, expand > head > for now.
I looked at the code, skb_clone shouldn't have any problem since ubuf callback is only called after the lower device DMA has done. I can modify the zerocopy len to 256 bytes so expand head should be OK as well. So we only need to prevent recycle skb. I also checked the device drivers, only a few device do RX buffers recycle. So there shouldn't be any problem.
I will add more comments here to make sure when ZEROCOPY flag is set, the ubuf callback should only be called when last reference to this skb is gone.
Thanks Shirley
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