[PATCH net-next 0/4] shrink struct ubuf_info

Pavel Begunkov
2022-09-23T16:40:28Z

struct ubuf_info is large but not all fields are needed for all
cases. We have limited space in io_uring for it and large ubuf_info
prevents some struct embedding, even though we use only a subset
of the fields. It's also not very clean trying to use this typeless
extra space.

Shrink struct ubuf_info to only necessary fields used in generic paths,
namely ->callback, ->refcnt and ->flags, which take only 16 bytes. And
make MSG_ZEROCOPY and some other users to embed it into a larger struct
ubuf_info_msgzc mimicking the former ubuf_info.

Note, xen/vhost may also have some cleaning on top by creating
new structs containing ubuf_info but with proper types.

Pavel Begunkov (4):
net: introduce struct ubuf_info_msgzc
xen/netback: use struct ubuf_info_msgzc
vhost/net: use struct ubuf_info_msgzc
net: shrink struct ubuf_info

drivers/net/xen-netback/common.h | 2 +-
drivers/net/xen-netback/interface.c | 4 +--
drivers/net/xen-netback/netback.c | 7 +++---
drivers/vhost/net.c | 15 ++++++------
include/linux/skbuff.h | 11 +++++++--
net/core/skbuff.c | 38 ++++++++++++++++-------------
net/ipv4/ip_output.c | 2 +-
net/ipv4/tcp.c | 2 +-
net/ipv6/ip6_output.c | 2 +-
9 files changed, 48 insertions(+), 35 deletions(-)

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2.37.2