Re: [RFC net-next v3 05/29] net: bvec specific path in zerocopy_sg_from_iter

From: Pavel Begunkov
Date: Tue Jul 05 2022 - 10:11:39 EST


On 7/5/22 03:28, David Ahern wrote:
On 7/4/22 7:31 AM, Pavel Begunkov wrote:
If the series is going to be picked up for 5.20, how about we delay
this one for 5.21? I'll have time to think about it (maybe moving
the skb managed flag setup inside?), and will anyway need to send
some omitted patches then.


I think it reads better for io_uring and future extensions for io_uring
to contain the optimized bvec iter handler and setting the managed flag.
Too many disjointed assumptions the way the code is now. By pulling that
into io_uring, core code does not make assumptions that "managed" means
bvec and no page references - rather that is embedded in the code that
cares.

Core code would still need to know when to remove the skb's managed
flag, e.g. in case of mixing. Can be worked out but with assumptions,
which doesn't look better that it currently is. I'll post a 5.20
rebased version and will iron it out on the way then.

--
Pavel Begunkov