diff options
Diffstat (limited to 'net/core/skbuff.c')
| -rw-r--r-- | net/core/skbuff.c | 78 |
1 files changed, 63 insertions, 15 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 10bde7c6db44..475183f37891 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -80,7 +80,6 @@ #include <linux/user_namespace.h> #include <linux/indirect_call_wrapper.h> -#include "datagram.h" #include "sock_destructor.h" struct kmem_cache *skbuff_head_cache __ro_after_init; @@ -204,7 +203,7 @@ static void __build_skb_around(struct sk_buff *skb, void *data, skb_set_end_offset(skb, size); skb->mac_header = (typeof(skb->mac_header))~0U; skb->transport_header = (typeof(skb->transport_header))~0U; - + skb->alloc_cpu = raw_smp_processor_id(); /* make sure we initialize shinfo sequentially */ shinfo = skb_shinfo(skb); memset(shinfo, 0, offsetof(struct skb_shared_info, dataref)); @@ -1037,6 +1036,7 @@ static void __copy_skb_header(struct sk_buff *new, const struct sk_buff *old) #ifdef CONFIG_NET_RX_BUSY_POLL CHECK_SKB_FIELD(napi_id); #endif + CHECK_SKB_FIELD(alloc_cpu); #ifdef CONFIG_XPS CHECK_SKB_FIELD(sender_cpu); #endif @@ -1339,18 +1339,11 @@ void msg_zerocopy_put_abort(struct ubuf_info *uarg, bool have_uref) } EXPORT_SYMBOL_GPL(msg_zerocopy_put_abort); -int skb_zerocopy_iter_dgram(struct sk_buff *skb, struct msghdr *msg, int len) -{ - return __zerocopy_sg_from_iter(skb->sk, skb, &msg->msg_iter, len); -} -EXPORT_SYMBOL_GPL(skb_zerocopy_iter_dgram); - int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, struct msghdr *msg, int len, struct ubuf_info *uarg) { struct ubuf_info *orig_uarg = skb_zcopy(skb); - struct iov_iter orig_iter = msg->msg_iter; int err, orig_len = skb->len; /* An skb can only point to one uarg. This edge case happens when @@ -1364,7 +1357,7 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb, struct sock *save_sk = skb->sk; /* Streams do not free skb on error. Reset to prev state. */ - msg->msg_iter = orig_iter; + iov_iter_revert(&msg->msg_iter, skb->len - orig_len); skb->sk = sk; ___pskb_trim(skb, orig_len); skb->sk = save_sk; @@ -5276,11 +5269,18 @@ bool skb_try_coalesce(struct sk_buff *to, struct sk_buff *from, if (skb_cloned(to)) return false; - /* The page pool signature of struct page will eventually figure out - * which pages can be recycled or not but for now let's prohibit slab - * allocated and page_pool allocated SKBs from being coalesced. + /* In general, avoid mixing slab allocated and page_pool allocated + * pages within the same SKB. However when @to is not pp_recycle and + * @from is cloned, we can transition frag pages from page_pool to + * reference counted. + * + * On the other hand, don't allow coalescing two pp_recycle SKBs if + * @from is cloned, in case the SKB is using page_pool fragment + * references (PP_FLAG_PAGE_FRAG). Since we only take full page + * references for cloned SKBs at the moment that would result in + * inconsistent reference counts. */ - if (to->pp_recycle != from->pp_recycle) + if (to->pp_recycle != (from->pp_recycle && !skb_cloned(from))) return false; if (len <= skb_tailroom(to)) { @@ -5594,7 +5594,7 @@ err_free: } EXPORT_SYMBOL(skb_vlan_untag); -int skb_ensure_writable(struct sk_buff *skb, int write_len) +int skb_ensure_writable(struct sk_buff *skb, unsigned int write_len) { if (!pskb_may_pull(skb, write_len)) return -ENOMEM; @@ -6479,3 +6479,51 @@ free_now: } EXPORT_SYMBOL(__skb_ext_put); #endif /* CONFIG_SKB_EXTENSIONS */ + +/** + * skb_attempt_defer_free - queue skb for remote freeing + * @skb: buffer + * + * Put @skb in a per-cpu list, using the cpu which + * allocated the skb/pages to reduce false sharing + * and memory zone spinlock contention. + */ +void skb_attempt_defer_free(struct sk_buff *skb) +{ + int cpu = skb->alloc_cpu; + struct softnet_data *sd; + unsigned long flags; + bool kick; + + if (WARN_ON_ONCE(cpu >= nr_cpu_ids) || + !cpu_online(cpu) || + cpu == raw_smp_processor_id()) { + __kfree_skb(skb); + return; + } + + sd = &per_cpu(softnet_data, cpu); + /* We do not send an IPI or any signal. + * Remote cpu will eventually call skb_defer_free_flush() + */ + spin_lock_irqsave(&sd->defer_lock, flags); + skb->next = sd->defer_list; + /* Paired with READ_ONCE() in skb_defer_free_flush() */ + WRITE_ONCE(sd->defer_list, skb); + sd->defer_count++; + + /* kick every time queue length reaches 128. + * This should avoid blocking in smp_call_function_single_async(). + * This condition should hardly be bit under normal conditions, + * unless cpu suddenly stopped to receive NIC interrupts. + */ + kick = sd->defer_count == 128; + + spin_unlock_irqrestore(&sd->defer_lock, flags); + + /* Make sure to trigger NET_RX_SOFTIRQ on the remote CPU + * if we are unlucky enough (this seems very unlikely). + */ + if (unlikely(kick)) + smp_call_function_single_async(cpu, &sd->defer_csd); +} |