Merge branch 'skbuff-bitfields'

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Jakub Kicinski says:

====================
net: skbuff: hide some bitfield members

There is a number of protocol or subsystem specific fields
in struct sk_buff which are only accessed by one subsystem.
We can wrap them in ifdefs with minimal code impact.

This gives us a better chance to save a 2B and a 4B holes
resulting with the following savings (assuming a lucky
kernel config):

-	/* size: 232, cachelines: 4, members: 28 */
-	/* sum members: 227, holes: 1, sum holes: 4 */
-	/* sum bitfield members: 8 bits (1 bytes) */
+	/* size: 224, cachelines: 4, members: 28 */
 	/* forced alignments: 2 */
-	/* last cacheline: 40 bytes */
+	/* last cacheline: 32 bytes */

I think that the changes shouldn't be too controversial.
The only one I'm not 100% sure of is the SCTP one,
12 extra LoC for one bit.. But it did fit squarely
in the "this bit has only one user" category.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Simon Horman <horms@kernel.org>

...

This commit is contained in:

David S. Miller 2023-04-19 13:04:31 +01:00

parent 4edd97fbdc 48d80c394d

commit fbb192a836

6 changed files with 41 additions and 9 deletions

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38

include/linux/skbuff.h

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2

include/net/sock.h

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3

net/core/dev.c

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2

net/core/skbuff.c

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3

net/sched/act_csum.c

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2

net/socket.c

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