diff options
| -rw-r--r-- | include/linux/skbuff.h | 4 | ||||
| -rw-r--r-- | net/core/dev.c | 16 | ||||
| -rw-r--r-- | net/core/skbuff.c | 428 |
3 files changed, 242 insertions, 206 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 0a4e91a2f873..6d0a33d1c0db 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1087,6 +1087,8 @@ 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); +struct sk_buff *napi_build_skb(void *data, unsigned int frag_size); + /** * alloc_skb - allocate a network buffer * @size: size to allocate @@ -2919,7 +2921,7 @@ static inline struct sk_buff *napi_alloc_skb(struct napi_struct *napi, } void napi_consume_skb(struct sk_buff *skb, int budget); -void __kfree_skb_flush(void); +void napi_skb_free_stolen_head(struct sk_buff *skb); void __kfree_skb_defer(struct sk_buff *skb); /** diff --git a/net/core/dev.c b/net/core/dev.c index ce6291bc2e16..ea9b46318d23 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4944,8 +4944,6 @@ static __latent_entropy void net_tx_action(struct softirq_action *h) else __kfree_skb_defer(skb); } - - __kfree_skb_flush(); } if (sd->output_queue) { @@ -6097,13 +6095,6 @@ struct packet_offload *gro_find_complete_by_type(__be16 type) } EXPORT_SYMBOL(gro_find_complete_by_type); -static void napi_skb_free_stolen_head(struct sk_buff *skb) -{ - skb_dst_drop(skb); - skb_ext_put(skb); - kmem_cache_free(skbuff_head_cache, skb); -} - static gro_result_t napi_skb_finish(struct napi_struct *napi, struct sk_buff *skb, gro_result_t ret) @@ -6117,7 +6108,7 @@ static gro_result_t napi_skb_finish(struct napi_struct *napi, if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD) napi_skb_free_stolen_head(skb); else - __kfree_skb(skb); + __kfree_skb_defer(skb); break; case GRO_HELD: @@ -7012,7 +7003,6 @@ static int napi_threaded_poll(void *data) __napi_poll(napi, &repoll); netpoll_poll_unlock(have); - __kfree_skb_flush(); local_bh_enable(); if (!repoll) @@ -7042,7 +7032,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) if (list_empty(&list)) { if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll)) - goto out; + return; break; } @@ -7069,8 +7059,6 @@ static __latent_entropy void net_rx_action(struct softirq_action *h) __raise_softirq_irqoff(NET_RX_SOFTIRQ); net_rps_action_and_irq_enable(sd); -out: - __kfree_skb_flush(); } struct netdev_adjacent { diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d380c7b5a12d..545a472273a5 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -119,151 +119,75 @@ static void skb_under_panic(struct sk_buff *skb, unsigned int sz, void *addr) skb_panic(skb, sz, addr, __func__); } -/* - * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells - * the caller if emergency pfmemalloc reserves are being used. If it is and - * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves - * may be used. Otherwise, the packet data may be discarded until enough - * memory is free - */ -#define kmalloc_reserve(size, gfp, node, pfmemalloc) \ - __kmalloc_reserve(size, gfp, node, _RET_IP_, pfmemalloc) - -static void *__kmalloc_reserve(size_t size, gfp_t flags, int node, - unsigned long ip, bool *pfmemalloc) -{ - void *obj; - bool ret_pfmemalloc = false; +#define NAPI_SKB_CACHE_SIZE 64 +#define NAPI_SKB_CACHE_BULK 16 +#define NAPI_SKB_CACHE_HALF (NAPI_SKB_CACHE_SIZE / 2) - /* - * Try a regular allocation, when that fails and we're not entitled - * to the reserves, fail. - */ - obj = kmalloc_node_track_caller(size, - flags | __GFP_NOMEMALLOC | __GFP_NOWARN, - node); - if (obj || !(gfp_pfmemalloc_allowed(flags))) - goto out; +struct napi_alloc_cache { + struct page_frag_cache page; + unsigned int skb_count; + void *skb_cache[NAPI_SKB_CACHE_SIZE]; +}; - /* Try again but now we are using pfmemalloc reserves */ - ret_pfmemalloc = true; - obj = kmalloc_node_track_caller(size, flags, node); +static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache); +static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache); -out: - if (pfmemalloc) - *pfmemalloc = ret_pfmemalloc; +static void *__alloc_frag_align(unsigned int fragsz, gfp_t gfp_mask, + unsigned int align_mask) +{ + struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); - return obj; + return page_frag_alloc_align(&nc->page, fragsz, gfp_mask, align_mask); } -/* Allocate a new skbuff. We do this ourselves so we can fill in a few - * 'private' fields and also do memory statistics to find all the - * [BEEP] leaks. - * - */ - -/** - * __alloc_skb - allocate a network buffer - * @size: size to allocate - * @gfp_mask: allocation mask - * @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache - * instead of head cache and allocate a cloned (child) skb. - * If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for - * allocations in case the data is required for writeback - * @node: numa node to allocate memory on - * - * Allocate a new &sk_buff. The returned buffer has no headroom and a - * tail room of at least size bytes. The object has a reference count - * of one. The return is the buffer. On a failure the return is %NULL. - * - * Buffers may only be allocated from interrupts using a @gfp_mask of - * %GFP_ATOMIC. - */ -struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, - int flags, int node) +void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) { - struct kmem_cache *cache; - struct skb_shared_info *shinfo; - struct sk_buff *skb; - u8 *data; - bool pfmemalloc; - - cache = (flags & SKB_ALLOC_FCLONE) - ? skbuff_fclone_cache : skbuff_head_cache; - - if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) - gfp_mask |= __GFP_MEMALLOC; - - /* Get the HEAD */ - skb = kmem_cache_alloc_node(cache, gfp_mask & ~__GFP_DMA, node); - if (!skb) - goto out; - prefetchw(skb); - - /* We do our best to align skb_shared_info on a separate cache - * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives - * aligned memory blocks, unless SLUB/SLAB debug is enabled. - * Both skb->head and skb_shared_info are cache line aligned. - */ - size = SKB_DATA_ALIGN(size); - size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); - if (!data) - goto nodata; - /* kmalloc(size) might give us more room than requested. - * Put skb_shared_info exactly at the end of allocated zone, - * to allow max possible filling before reallocation. - */ - size = SKB_WITH_OVERHEAD(ksize(data)); - prefetchw(data + size); - - /* - * Only clear those fields we need to clear, not those that we will - * actually initialise below. Hence, don't put any more fields after - * the tail pointer in struct sk_buff! - */ - memset(skb, 0, offsetof(struct sk_buff, tail)); - /* Account for allocated memory : skb + skb->head */ - skb->truesize = SKB_TRUESIZE(size); - skb->pfmemalloc = pfmemalloc; - 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; + fragsz = SKB_DATA_ALIGN(fragsz); - /* 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 __alloc_frag_align(fragsz, GFP_ATOMIC, align_mask); +} +EXPORT_SYMBOL(__napi_alloc_frag_align); - if (flags & SKB_ALLOC_FCLONE) { - struct sk_buff_fclones *fclones; +void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) +{ + struct page_frag_cache *nc; + void *data; - fclones = container_of(skb, struct sk_buff_fclones, skb1); + fragsz = SKB_DATA_ALIGN(fragsz); + if (in_irq() || irqs_disabled()) { + nc = this_cpu_ptr(&netdev_alloc_cache); + data = page_frag_alloc_align(nc, fragsz, GFP_ATOMIC, align_mask); + } else { + local_bh_disable(); + data = __alloc_frag_align(fragsz, GFP_ATOMIC, align_mask); + local_bh_enable(); + } + return data; +} +EXPORT_SYMBOL(__netdev_alloc_frag_align); - skb->fclone = SKB_FCLONE_ORIG; - refcount_set(&fclones->fclone_ref, 1); +static struct sk_buff *napi_skb_cache_get(void) +{ + struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + struct sk_buff *skb; - fclones->skb2.fclone = SKB_FCLONE_CLONE; - } + if (unlikely(!nc->skb_count)) + nc->skb_count = kmem_cache_alloc_bulk(skbuff_head_cache, + GFP_ATOMIC, + NAPI_SKB_CACHE_BULK, + nc->skb_cache); + if (unlikely(!nc->skb_count)) + return NULL; - skb_set_kcov_handle(skb, kcov_common_handle()); + skb = nc->skb_cache[--nc->skb_count]; + kasan_unpoison_object_data(skbuff_head_cache, skb); -out: return skb; -nodata: - kmem_cache_free(cache, skb); - skb = NULL; - goto out; } -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) +static void __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); @@ -286,8 +210,6 @@ static struct sk_buff *__build_skb_around(struct sk_buff *skb, atomic_set(&shinfo->dataref, 1); skb_set_kcov_handle(skb, kcov_common_handle()); - - return skb; } /** @@ -318,8 +240,9 @@ struct sk_buff *__build_skb(void *data, unsigned int frag_size) return NULL; memset(skb, 0, offsetof(struct sk_buff, tail)); + __build_skb_around(skb, data, frag_size); - return __build_skb_around(skb, data, frag_size); + return skb; } /* build_skb() is wrapper over __build_skb(), that specifically @@ -352,9 +275,9 @@ struct sk_buff *build_skb_around(struct sk_buff *skb, if (unlikely(!skb)) return NULL; - skb = __build_skb_around(skb, data, frag_size); + __build_skb_around(skb, data, frag_size); - if (skb && frag_size) { + if (frag_size) { skb->head_frag = 1; if (page_is_pfmemalloc(virt_to_head_page(data))) skb->pfmemalloc = 1; @@ -363,50 +286,178 @@ struct sk_buff *build_skb_around(struct sk_buff *skb, } EXPORT_SYMBOL(build_skb_around); -#define NAPI_SKB_CACHE_SIZE 64 +/** + * __napi_build_skb - build a network buffer + * @data: data buffer provided by caller + * @frag_size: size of data, or 0 if head was kmalloced + * + * Version of __build_skb() that uses NAPI percpu caches to obtain + * skbuff_head instead of inplace allocation. + * + * Returns a new &sk_buff on success, %NULL on allocation failure. + */ +static struct sk_buff *__napi_build_skb(void *data, unsigned int frag_size) +{ + struct sk_buff *skb; -struct napi_alloc_cache { - struct page_frag_cache page; - unsigned int skb_count; - void *skb_cache[NAPI_SKB_CACHE_SIZE]; -}; + skb = napi_skb_cache_get(); + if (unlikely(!skb)) + return NULL; -static DEFINE_PER_CPU(struct page_frag_cache, netdev_alloc_cache); -static DEFINE_PER_CPU(struct napi_alloc_cache, napi_alloc_cache); + memset(skb, 0, offsetof(struct sk_buff, tail)); + __build_skb_around(skb, data, frag_size); -static void *__alloc_frag_align(unsigned int fragsz, gfp_t gfp_mask, - unsigned int align_mask) + return skb; +} + +/** + * napi_build_skb - build a network buffer + * @data: data buffer provided by caller + * @frag_size: size of data, or 0 if head was kmalloced + * + * Version of __napi_build_skb() that takes care of skb->head_frag + * and skb->pfmemalloc when the data is a page or page fragment. + * + * Returns a new &sk_buff on success, %NULL on allocation failure. + */ +struct sk_buff *napi_build_skb(void *data, unsigned int frag_size) { - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + struct sk_buff *skb = __napi_build_skb(data, frag_size); - return page_frag_alloc_align(&nc->page, fragsz, gfp_mask, align_mask); + if (likely(skb) && frag_size) { + skb->head_frag = 1; + skb_propagate_pfmemalloc(virt_to_head_page(data), skb); + } + + return skb; } +EXPORT_SYMBOL(napi_build_skb); -void *__napi_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) +/* + * kmalloc_reserve is a wrapper around kmalloc_node_track_caller that tells + * the caller if emergency pfmemalloc reserves are being used. If it is and + * the socket is later found to be SOCK_MEMALLOC then PFMEMALLOC reserves + * may be used. Otherwise, the packet data may be discarded until enough + * memory is free + */ +static void *kmalloc_reserve(size_t size, gfp_t flags, int node, + bool *pfmemalloc) { - fragsz = SKB_DATA_ALIGN(fragsz); + void *obj; + bool ret_pfmemalloc = false; - return __alloc_frag_align(fragsz, GFP_ATOMIC, align_mask); + /* + * Try a regular allocation, when that fails and we're not entitled + * to the reserves, fail. + */ + obj = kmalloc_node_track_caller(size, + flags | __GFP_NOMEMALLOC | __GFP_NOWARN, + node); + if (obj || !(gfp_pfmemalloc_allowed(flags))) + goto out; + + /* Try again but now we are using pfmemalloc reserves */ + ret_pfmemalloc = true; + obj = kmalloc_node_track_caller(size, flags, node); + +out: + if (pfmemalloc) + *pfmemalloc = ret_pfmemalloc; + + return obj; } -EXPORT_SYMBOL(__napi_alloc_frag_align); -void *__netdev_alloc_frag_align(unsigned int fragsz, unsigned int align_mask) +/* Allocate a new skbuff. We do this ourselves so we can fill in a few + * 'private' fields and also do memory statistics to find all the + * [BEEP] leaks. + * + */ + +/** + * __alloc_skb - allocate a network buffer + * @size: size to allocate + * @gfp_mask: allocation mask + * @flags: If SKB_ALLOC_FCLONE is set, allocate from fclone cache + * instead of head cache and allocate a cloned (child) skb. + * If SKB_ALLOC_RX is set, __GFP_MEMALLOC will be used for + * allocations in case the data is required for writeback + * @node: numa node to allocate memory on + * + * Allocate a new &sk_buff. The returned buffer has no headroom and a + * tail room of at least size bytes. The object has a reference count + * of one. The return is the buffer. On a failure the return is %NULL. + * + * Buffers may only be allocated from interrupts using a @gfp_mask of + * %GFP_ATOMIC. + */ +struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, + int flags, int node) { - struct page_frag_cache *nc; - void *data; + struct kmem_cache *cache; + struct sk_buff *skb; + u8 *data; + bool pfmemalloc; - fragsz = SKB_DATA_ALIGN(fragsz); - if (in_irq() || irqs_disabled()) { - nc = this_cpu_ptr(&netdev_alloc_cache); - data = page_frag_alloc_align(nc, fragsz, GFP_ATOMIC, align_mask); - } else { - local_bh_disable(); - data = __alloc_frag_align(fragsz, GFP_ATOMIC, align_mask); - local_bh_enable(); + cache = (flags & SKB_ALLOC_FCLONE) + ? skbuff_fclone_cache : skbuff_head_cache; + + if (sk_memalloc_socks() && (flags & SKB_ALLOC_RX)) + gfp_mask |= __GFP_MEMALLOC; + + /* Get the HEAD */ + if ((flags & (SKB_ALLOC_FCLONE | SKB_ALLOC_NAPI)) == SKB_ALLOC_NAPI && + likely(node == NUMA_NO_NODE || node == numa_mem_id())) + skb = napi_skb_cache_get(); + else + skb = kmem_cache_alloc_node(cache, gfp_mask & ~GFP_DMA, node); + if (unlikely(!skb)) + return NULL; + prefetchw(skb); + + /* We do our best to align skb_shared_info on a separate cache + * line. It usually works because kmalloc(X > SMP_CACHE_BYTES) gives + * aligned memory blocks, unless SLUB/SLAB debug is enabled. + * Both skb->head and skb_shared_info are cache line aligned. + */ + size = SKB_DATA_ALIGN(size); + size += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); + if (unlikely(!data)) + goto nodata; + /* kmalloc(size) might give us more room than requested. + * Put skb_shared_info exactly at the end of allocated zone, + * to allow max possible filling before reallocation. + */ + size = SKB_WITH_OVERHEAD(ksize(data)); + prefetchw(data + size); + + /* + * Only clear those fields we need to clear, not those that we will + * actually initialise below. Hence, don't put any more fields after + * the tail pointer in struct sk_buff! + */ + memset(skb, 0, offsetof(struct sk_buff, tail)); + __build_skb_around(skb, data, 0); + skb->pfmemalloc = pfmemalloc; + + if (flags & SKB_ALLOC_FCLONE) { + struct sk_buff_fclones *fclones; + + fclones = container_of(skb, struct sk_buff_fclones, skb1); + + skb->fclone = SKB_FCLONE_ORIG; + refcount_set(&fclones->fclone_ref, 1); + + fclones->skb2.fclone = SKB_FCLONE_CLONE; } - return data; + + return skb; + +nodata: + kmem_cache_free(cache, skb); + return NULL; } -EXPORT_SYMBOL(__netdev_alloc_frag_align); +EXPORT_SYMBOL(__alloc_skb); /** * __netdev_alloc_skb - allocate an skbuff for rx on a specific device @@ -511,7 +562,8 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, if (len <= SKB_WITH_OVERHEAD(1024) || len > SKB_WITH_OVERHEAD(PAGE_SIZE) || (gfp_mask & (__GFP_DIRECT_RECLAIM | GFP_DMA))) { - skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX, NUMA_NO_NODE); + skb = __alloc_skb(len, gfp_mask, SKB_ALLOC_RX | SKB_ALLOC_NAPI, + NUMA_NO_NODE); if (!skb) goto skb_fail; goto skb_success; @@ -528,7 +580,7 @@ struct sk_buff *__napi_alloc_skb(struct napi_struct *napi, unsigned int len, if (unlikely(!data)) return NULL; - skb = __build_skb(data, len); + skb = __napi_build_skb(data, len); if (unlikely(!skb)) { skb_free_frag(data); return NULL; @@ -859,43 +911,36 @@ void __consume_stateless_skb(struct sk_buff *skb) kfree_skbmem(skb); } -void __kfree_skb_flush(void) +static void napi_skb_cache_put(struct sk_buff *skb) { struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); + u32 i; - /* flush skb_cache if containing objects */ - if (nc->skb_count) { - kmem_cache_free_bulk(skbuff_head_cache, nc->skb_count, - nc->skb_cache); - nc->skb_count = 0; - } -} - -static inline void _kfree_skb_defer(struct sk_buff *skb) -{ - struct napi_alloc_cache *nc = this_cpu_ptr(&napi_alloc_cache); - - /* drop skb->head and call any destructors for packet */ - skb_release_all(skb); - - /* record skb to CPU local list */ + kasan_poison_object_data(skbuff_head_cache, skb); nc->skb_cache[nc->skb_count++] = skb; -#ifdef CONFIG_SLUB - /* SLUB writes into objects when freeing */ - prefetchw(skb); -#endif - - /* flush skb_cache if it is filled */ if (unlikely(nc->skb_count == NAPI_SKB_CACHE_SIZE)) { - kmem_cache_free_bulk(skbuff_head_cache, NAPI_SKB_CACHE_SIZE, - nc->skb_cache); - nc->skb_count = 0; + for (i = NAPI_SKB_CACHE_HALF; i < NAPI_SKB_CACHE_SIZE; i++) + kasan_unpoison_object_data(skbuff_head_cache, + nc->skb_cache[i]); + + kmem_cache_free_bulk(skbuff_head_cache, NAPI_SKB_CACHE_HALF, + nc->skb_cache + NAPI_SKB_CACHE_HALF); + nc->skb_count = NAPI_SKB_CACHE_HALF; } } + void __kfree_skb_defer(struct sk_buff *skb) { - _kfree_skb_defer(skb); + skb_release_all(skb); + napi_skb_cache_put(skb); +} + +void napi_skb_free_stolen_head(struct sk_buff *skb) +{ + skb_dst_drop(skb); + skb_ext_put(skb); + napi_skb_cache_put(skb); } void napi_consume_skb(struct sk_buff *skb, int budget) @@ -920,7 +965,8 @@ void napi_consume_skb(struct sk_buff *skb, int budget) return; } - _kfree_skb_defer(skb); + skb_release_all(skb); + napi_skb_cache_put(skb); } EXPORT_SYMBOL(napi_consume_skb); |