net: add skbuff_clear() helper

Browse source

clang is unable to inline the memset() calls in net/core/skbuff.c
when initializing allocated sk_buff.

memset(skb, 0, offsetof(struct sk_buff, tail));

This is unfortunate, because:

1) calling external memset_orig() helper adds a call/ret and
   typical setup cost.

2) offsetof(struct sk_buff, tail) == 0xb8 = 0x80 + 0x38

   On x86_64, memset_orig() performs two 64 bytes clear,
   then has to loop 7 times to clear the final 56 bytes.

skbuff_clear() makes sure the minimal and optimal code
is generated.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260109203836.1667441-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

Eric Dumazet 2026-01-09 20:38:36 +00:00 • committed by Jakub Kicinski

parent d7161b0790

commit 0391ab577c

1 changed files with 22 additions and 10 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

32

net/core/skbuff.c

View file