diff options
| author | Eric Dumazet <edumazet@google.com> | 2021-11-24 12:24:45 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-11-25 21:03:31 -0800 |
| commit | 0bd28476f6363c7ccc841fe6a0ab0dd1fdb822f6 (patch) | |
| tree | 8d1bfa9f18c5d8082794f804dea59d21312a88c4 /include/net/gro.h | |
| parent | 703319094c9c2bf34f65d3496ccb350149fdd14b (diff) | |
gro: optimize skb_gro_postpull_rcsum()
We can leverage third argument to csum_partial():
X = csum_sub(X, csum_partial(start, len, 0));
-->
X = csum_add(X, ~csum_partial(start, len, 0));
-->
X = ~csum_partial(start, len, ~X);
This removes one add/adc pair and its dependency against the carry flag.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/net/gro.h')
| -rw-r--r-- | include/net/gro.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/net/gro.h b/include/net/gro.h index 9c22a010369c..b1139fca7c43 100644 --- a/include/net/gro.h +++ b/include/net/gro.h @@ -173,8 +173,8 @@ static inline void skb_gro_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len) { if (NAPI_GRO_CB(skb)->csum_valid) - NAPI_GRO_CB(skb)->csum = csum_sub(NAPI_GRO_CB(skb)->csum, - csum_partial(start, len, 0)); + NAPI_GRO_CB(skb)->csum = ~csum_partial(start, len, + ~NAPI_GRO_CB(skb)->csum); } /* GRO checksum functions. These are logical equivalents of the normal |