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| author | Jakub Kicinski <kuba@kernel.org> | 2021-11-25 21:03:33 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2021-11-25 21:03:33 -0800 |
| commit | 35bf8c86eeb8ae609f61c43aeab3b530fedcf1b4 (patch) | |
| tree | 7f17a01eb6164d66c713a0d18fde1ffa231707e4 | |
| parent | 703319094c9c2bf34f65d3496ccb350149fdd14b (diff) | |
| parent | 29c3002644bdd653f6ec6407d25135d0a4f7cefb (diff) | |
| download | lwn-35bf8c86eeb8ae609f61c43aeab3b530fedcf1b4.tar.gz lwn-35bf8c86eeb8ae609f61c43aeab3b530fedcf1b4.zip | |
Merge branch 'net-small-csum-optimizations'
Eric Dumazet says:
====================
net: small csum optimizations
After recent x86 csum_partial() optimizations, we can more easily
see in kernel profiles costs of add/adc operations that could
be avoided, by feeding a non zero third argument to csum_partial()
====================
Link: https://lore.kernel.org/r/20211124202446.2917972-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/linux/skbuff.h | 6 | ||||
| -rw-r--r-- | include/net/gro.h | 4 |
2 files changed, 7 insertions, 3 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index eba256af64a5..eae4bd3237a4 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3485,7 +3485,11 @@ __skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len, static inline void skb_postpull_rcsum(struct sk_buff *skb, const void *start, unsigned int len) { - __skb_postpull_rcsum(skb, start, len, 0); + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->csum = ~csum_partial(start, len, ~skb->csum); + else if (skb->ip_summed == CHECKSUM_PARTIAL && + skb_checksum_start_offset(skb) < 0) + skb->ip_summed = CHECKSUM_NONE; } static __always_inline void 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 |