diff options
| author | Jakub Kicinski <kuba@kernel.org> | 2023-02-07 10:57:57 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-02-07 11:00:03 -0800 |
| commit | 383d9f87a06dd923c4fd0fdcb65b58258851f545 (patch) | |
| tree | 63eee2d53a03648d9d0aeb3a2535315a0dc6bf25 /include/linux | |
| parent | 61d731e6538dc44abf2dca6e77098ec6e85f7cc2 (diff) | |
| parent | bf9f1baa279f0758dc2297080360c5a616843927 (diff) | |
Merge branch 'net-core-use-a-dedicated-kmem_cache-for-skb-head-allocs'
Eric Dumazet says:
====================
net: core: use a dedicated kmem_cache for skb head allocs
Our profile data show that using kmalloc(non_const_size)/kfree(ptr)
has a certain cost, because kfree(ptr) has to pull a 'struct page'
in cpu caches.
Using a dedicated kmem_cache for TCP skb->head allocations makes
a difference, both in cpu cycles and memory savings.
This kmem_cache could also be used for GRO skb allocations,
this is left as a future exercise.
====================
Link: https://lore.kernel.org/r/20230206173103.2617121-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/skbuff.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1fa95b916342..c3df3b55da97 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -255,6 +255,14 @@ #define SKB_DATA_ALIGN(X) ALIGN(X, SMP_CACHE_BYTES) #define SKB_WITH_OVERHEAD(X) \ ((X) - SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) + +/* For X bytes available in skb->head, what is the minimal + * allocation needed, knowing struct skb_shared_info needs + * to be aligned. + */ +#define SKB_HEAD_ALIGN(X) (SKB_DATA_ALIGN(X) + \ + SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) + #define SKB_MAX_ORDER(X, ORDER) \ SKB_WITH_OVERHEAD((PAGE_SIZE << (ORDER)) - (X)) #define SKB_MAX_HEAD(X) (SKB_MAX_ORDER((X), 0)) |