diff options
author | Jesper Dangaard Brouer <brouer@redhat.com> | 2019-04-12 17:07:37 +0200 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2019-04-17 19:09:24 -0700 |
commit | ba0509b6881efd0c8b26c36490cba87d8fb324c0 (patch) | |
tree | 823c2b8b7faca2fc53cbda830d77572be132b1c6 | |
parent | 77361825bb01ecadf3ac8622e2e4dbc28806e858 (diff) | |
download | linux-stable-ba0509b6881efd0c8b26c36490cba87d8fb324c0.tar.gz linux-stable-ba0509b6881efd0c8b26c36490cba87d8fb324c0.tar.bz2 linux-stable-ba0509b6881efd0c8b26c36490cba87d8fb324c0.zip |
net: core: introduce build_skb_around
The function build_skb() also have the responsibility to allocate and clear
the SKB structure. Introduce a new function build_skb_around(), that moves
the responsibility of allocation and clearing to the caller. This allows
caller to use kmem_cache (slab/slub) bulk allocation API.
Next patch use this function combined with kmem_cache_alloc_bulk.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
-rw-r--r-- | include/linux/skbuff.h | 2 | ||||
-rw-r--r-- | net/core/skbuff.c | 71 |
2 files changed, 54 insertions, 19 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index a06275a618f0..e81f2b0e8a83 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1042,6 +1042,8 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t priority, int flags, int node); struct sk_buff *__build_skb(void *data, unsigned int frag_size); struct sk_buff *build_skb(void *data, unsigned int frag_size); +struct sk_buff *build_skb_around(struct sk_buff *skb, + void *data, unsigned int frag_size); /** * alloc_skb - allocate a network buffer diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9901f5322852..087622298d77 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -258,6 +258,33 @@ nodata: } EXPORT_SYMBOL(__alloc_skb); +/* Caller must provide SKB that is memset cleared */ +static struct sk_buff *__build_skb_around(struct sk_buff *skb, + void *data, unsigned int frag_size) +{ + struct skb_shared_info *shinfo; + unsigned int size = frag_size ? : ksize(data); + + size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + + /* Assumes caller memset cleared SKB */ + skb->truesize = SKB_TRUESIZE(size); + refcount_set(&skb->users, 1); + skb->head = data; + skb->data = data; + skb_reset_tail_pointer(skb); + skb->end = skb->tail + size; + skb->mac_header = (typeof(skb->mac_header))~0U; + skb->transport_header = (typeof(skb->transport_header))~0U; + + /* make sure we initialize shinfo sequentially */ + shinfo = skb_shinfo(skb); + memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); + atomic_set(&shinfo->dataref, 1); + + return skb; +} + /** * __build_skb - build a network buffer * @data: data buffer provided by caller @@ -279,32 +306,15 @@ EXPORT_SYMBOL(__alloc_skb); */ struct sk_buff *__build_skb(void *data, unsigned int frag_size) { - struct skb_shared_info *shinfo; struct sk_buff *skb; - unsigned int size = frag_size ? : ksize(data); skb = kmem_cache_alloc(skbuff_head_cache, GFP_ATOMIC); - if (!skb) + if (unlikely(!skb)) return NULL; - size -= SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - memset(skb, 0, offsetof(struct sk_buff, tail)); - skb->truesize = SKB_TRUESIZE(size); - refcount_set(&skb->users, 1); - skb->head = data; - skb->data = data; - skb_reset_tail_pointer(skb); - skb->end = skb->tail + size; - skb->mac_header = (typeof(skb->mac_header))~0U; - skb->transport_header = (typeof(skb->transport_header))~0U; - /* make sure we initialize shinfo sequentially */ - shinfo = skb_shinfo(skb); - memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); - atomic_set(&shinfo->dataref, 1); - - return skb; + return __build_skb_around(skb, data, frag_size); } /* build_skb() is wrapper over __build_skb(), that specifically @@ -325,6 +335,29 @@ struct sk_buff *build_skb(void *data, unsigned int frag_size) } EXPORT_SYMBOL(build_skb); +/** + * build_skb_around - build a network buffer around provided skb + * @skb: sk_buff provide by caller, must be memset cleared + * @data: data buffer provided by caller + * @frag_size: size of data, or 0 if head was kmalloced + */ +struct sk_buff *build_skb_around(struct sk_buff *skb, + void *data, unsigned int frag_size) +{ + if (unlikely(!skb)) + return NULL; + + skb = __build_skb_around(skb, data, frag_size); + + if (skb && frag_size) { + skb->head_frag = 1; + if (page_is_pfmemalloc(virt_to_head_page(data))) + skb->pfmemalloc = 1; + } + return skb; +} +EXPORT_SYMBOL(build_skb_around); + #define NAPI_SKB_CACHE_SIZE 64 struct napi_alloc_cache { |