Messages in this thread | | | Subject | Re: [PATCH V3 2/8] Add a new zerocopy device flag | From | Shirley Ma <> | Date | Tue, 03 May 2011 10:42:50 -0700 |
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On Mon, 2011-05-02 at 22:53 +0300, Michael S. Tsirkin wrote: > On Mon, May 02, 2011 at 11:47:08AM -0700, Shirley Ma wrote: > > On Mon, 2011-05-02 at 13:42 +0300, Michael S. Tsirkin wrote: > > > This comment should specify what exactly is the promise the > > > device makes by setting this flag. Specifically, the > > > condition is that no skb fragments are used > > > after the uinfo callback has been called. > > > > > > The way it's implemented, it probably means the device > > > should not use any of skb_clone, expand head etc. > > > > Agree. Or maybe force a copy when device uses skb_clone, expand > > head ...? > > > > Thanks > > Shirley > > Copy from userspace upfront without locking is probably cheaper?
Better to prevent this kind of skbs to be used in skb_clone, expand head for now.
Thanks Shirley
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