From patchwork Tue Dec 21 15:35:25 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 12689965 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E9489C433FE for ; Tue, 21 Dec 2021 15:36:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239439AbhLUPgA (ORCPT ); Tue, 21 Dec 2021 10:36:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239410AbhLUPf4 (ORCPT ); Tue, 21 Dec 2021 10:35:56 -0500 Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92A7FC061401; Tue, 21 Dec 2021 07:35:56 -0800 (PST) Received: by mail-wr1-x436.google.com with SMTP id e5so27695561wrc.5; Tue, 21 Dec 2021 07:35:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=LPkWHJSnV5nNM7itLbmwC1bFPV13/RJSG50oK6FXZpk=; b=aP99VNZHpGh/sW7pp/qKJsclA1Fn5ykT6uWK+h4+RjpoU2C5Qdk2J8LD660Y+bzBhN LBhqGRyfX20Zur2HNee0txnRfNBFNd7u11PN9t95MuiaqZXvRP/2gjZEL9Qix7+DG7Xw dYDo+O8B3XqMQbZpfY565K/0mZzfV9A/93O2VVfGMjYFQDHAkidzMEJYn+pnhfbZmcz4 lmU8g8fzPrTABKZIT31H/IxBDLXmSyj2UNKLxvr46Oel9Q/kCL+8r3DeVt9eyWW9Nrlx JKb/Tx0DCYRReZhM6eNipu4HzKiLRE7lbno6Z54bLe2YNZ4hbjZl7M5C0rLHDCkINbNk qL/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=LPkWHJSnV5nNM7itLbmwC1bFPV13/RJSG50oK6FXZpk=; b=3VKfIPsKov8cP1Ex+5jASbNq0am0TBc1L4Z25AZcxjSaoRy522Q/jXb1XKV0I8hdxT YJQTJ6LU7vBtyZaFnCf51rtuTzD3Of3m8kKgGpP50MX3OIMiEgP2eDHRFgCTmBtjNoxS 2zlUu9Cix52Ykm+MB7xInF+3oV7dR0zpR22E2PHr7J6xrvdO03PpbO9biiql+RRu2ty4 4zBwWOAgIlRrhUwr6Sdhhe3CbdBJU40n5lJpmu+NNQXdI0O1Yje5WhLpdyLwGokw42gP MOfLpYW/KKCBMn5BixYtbvrvZenVe5IAbt+yom9RNtfU9y+iI74wiNHr/rLaG2/G5hEm TSLw== X-Gm-Message-State: AOAM533AgRRZzobHrf0r+Zy9ls01lBB51fKvFSyl73PzcUEG3YfkjLuq 3y7mLvP3IBlz71Lu/SXVrmYK0AMnhxw= X-Google-Smtp-Source: ABdhPJzhh+SYfefwdTfRXydLxmvAmvewcVnrFwXXe1Aq14C06o7daYcskdkAbxXrxd46+cNI/mJkxg== X-Received: by 2002:adf:e109:: with SMTP id t9mr2985003wrz.387.1640100955072; Tue, 21 Dec 2021 07:35:55 -0800 (PST) Received: from 127.0.0.1localhost ([148.252.128.24]) by smtp.gmail.com with ESMTPSA id z11sm2946019wmf.9.2021.12.21.07.35.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Dec 2021 07:35:54 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jakub Kicinski , Jonathan Lemon , "David S . Miller" , Willem de Bruijn , Eric Dumazet , David Ahern , Jens Axboe , Pavel Begunkov Subject: [RFC v2 03/19] net: add zerocopy_sg_from_iter for bvec Date: Tue, 21 Dec 2021 15:35:25 +0000 Message-Id: <162b7096c1a8e31743b692a229bac0c06a64c75c.1640029579.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.34.1 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 a separate path for bvec iterators in __zerocopy_sg_from_iter, first it's quite faster but also will be needed to optimise out get/put_page() Signed-off-by: Pavel Begunkov --- net/core/datagram.c | 50 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/net/core/datagram.c b/net/core/datagram.c index ee290776c661..cb1e34fbcd44 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -616,11 +616,61 @@ 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 ret, frag = skb_shinfo(skb)->nr_frags; + struct bvec_iter bi; + struct bio_vec v; + 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) { + if (frag == MAX_SKB_FRAGS) { + ret = -EMSGSIZE; + goto out; + } + + 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); + } + ret = 0; +out: + 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); + } + + from->bvec += bi.bi_idx; + from->nr_segs -= bi.bi_idx; + from->count = bi.bi_size; + from->iov_offset = bi.bi_bvec_done; + 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;