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[188.28.125.106]) by smtp.gmail.com with ESMTPSA id t21-20020a05640203d500b0043573c59ea0sm9758451edw.90.2022.06.28.11.59.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 11:59:58 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "David S . Miller" , Jakub Kicinski , Jonathan Lemon , Willem de Bruijn , Jens Axboe , kernel-team@fb.com, Pavel Begunkov Subject: [RFC net-next v3 05/29] net: bvec specific path in zerocopy_sg_from_iter Date: Tue, 28 Jun 2022 19:56:27 +0100 Message-Id: <5143111391e771dc97237e2a5e6a74223ef8f15f.1653992701.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC Add an bvec specialised and optimised path in zerocopy_sg_from_iter. It'll be used later for {get,put}_page() optimisations. Signed-off-by: Pavel Begunkov --- net/core/datagram.c | 47 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/net/core/datagram.c b/net/core/datagram.c index 50f4faeea76c..5237cb533bb4 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -613,11 +613,58 @@ int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, } EXPORT_SYMBOL(skb_copy_datagram_from_iter); +static int __zerocopy_sg_from_bvec(struct sock *sk, struct sk_buff *skb, + struct iov_iter *from, size_t length) +{ + int frag = skb_shinfo(skb)->nr_frags; + int ret = 0; + struct bvec_iter bi; + ssize_t copied = 0; + unsigned long truesize = 0; + + bi.bi_size = min(from->count, length); + bi.bi_bvec_done = from->iov_offset; + bi.bi_idx = 0; + + while (bi.bi_size && frag < MAX_SKB_FRAGS) { + struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi); + + copied += v.bv_len; + truesize += PAGE_ALIGN(v.bv_len + v.bv_offset); + get_page(v.bv_page); + skb_fill_page_desc(skb, frag++, v.bv_page, v.bv_offset, v.bv_len); + bvec_iter_advance_single(from->bvec, &bi, v.bv_len); + } + if (bi.bi_size) + ret = -EMSGSIZE; + + from->bvec += bi.bi_idx; + from->nr_segs -= bi.bi_idx; + from->count = bi.bi_size; + from->iov_offset = bi.bi_bvec_done; + + skb->data_len += copied; + skb->len += copied; + skb->truesize += truesize; + + if (sk && sk->sk_type == SOCK_STREAM) { + sk_wmem_queued_add(sk, truesize); + if (!skb_zcopy_pure(skb)) + sk_mem_charge(sk, truesize); + } else { + refcount_add(truesize, &skb->sk->sk_wmem_alloc); + } + return ret; +} + int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb, struct iov_iter *from, size_t length) { int frag = skb_shinfo(skb)->nr_frags; + if (iov_iter_is_bvec(from)) + return __zerocopy_sg_from_bvec(sk, skb, from, length); + while (length && iov_iter_count(from)) { struct page *pages[MAX_SKB_FRAGS]; struct page *last_head = NULL;