From patchwork Fri Nov 27 17:38:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Wunderlich X-Patchwork-Id: 18229 X-Patchwork-Delegate: sw@simonwunderlich.de Return-Path: X-Original-To: patchwork@open-mesh.org Delivered-To: patchwork@open-mesh.org Received: from diktynna.open-mesh.org (localhost [IPv6:::1]) by diktynna.open-mesh.org (Postfix) with ESMTP id 47344821A4; Fri, 27 Nov 2020 18:48:17 +0100 (CET) Received: from simonwunderlich.de (simonwunderlich.de [79.140.42.25]) by diktynna.open-mesh.org (Postfix) with ESMTPS id A59ED807E7 for ; Fri, 27 Nov 2020 18:48:14 +0100 (CET) Received: from kero.packetmixer.de (p200300c59712a4e04204e2f79fd8c031.dip0.t-ipconnect.de [IPv6:2003:c5:9712:a4e0:4204:e2f7:9fd8:c031]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simonwunderlich.de (Postfix) with ESMTPSA id BCB38174061; Fri, 27 Nov 2020 18:38:58 +0100 (CET) From: Simon Wunderlich To: davem@davemloft.net, kuba@kernel.org Subject: [PATCH 2/3] batman-adv: Reserve needed_*room for fragments Date: Fri, 27 Nov 2020 18:38:48 +0100 Message-Id: <20201127173849.19208-3-sw@simonwunderlich.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20201127173849.19208-1-sw@simonwunderlich.de> References: <20201127173849.19208-1-sw@simonwunderlich.de> MIME-Version: 1.0 ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=open-mesh.org; s=20121; t=1606499294; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=d6CK7/FFgdy2qANPMl4OPgmCdAMU3HpWiOjaiGQaPCc=; b=PaHFWLmiOOdYuYIj+MuKklvYDOx4v9kDaRca2yyb0K7teDPIFmi0IinB7jGfe2jIfBOyre ZBKHDEOKzl0/yG1XXTnGzcQY0ZpHXSdOLUd29Ebt65Yp5arIYhSVLoE3UK4yLE1i49VV7Z 3PPfv1CDjVS4hiqxcg9o2ZGe7JsxzwQ= ARC-Seal: i=1; s=20121; d=open-mesh.org; t=1606499294; a=rsa-sha256; cv=none; b=RepzvAzZvN4mVlwh4EOW42YQq5NMHOuvEDm84UJ5pl9y1EAI73CgUlWv2ERgWx2OUIS8+1 4/+e7iIc1/0cSF7JnZPuJoHxBUc2Wdw0HJtNdA58e1qWzU6Air1IzKXYVeh5+U+f7ZUckI f5osKhdpgww8eTeQZDUAbOOWu+d2Hb0= ARC-Authentication-Results: i=1; diktynna.open-mesh.org; dkim=none; spf=pass (diktynna.open-mesh.org: domain of sw@simonwunderlich.de designates 79.140.42.25 as permitted sender) smtp.mailfrom=sw@simonwunderlich.de Message-ID-Hash: JFWIZYTDPDQTWJXHBKZUIAYM2WBGFBHA X-Message-ID-Hash: JFWIZYTDPDQTWJXHBKZUIAYM2WBGFBHA X-MailFrom: sw@simonwunderlich.de X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; header-match-b.a.t.m.a.n.lists.open-mesh.org-0; header-match-b.a.t.m.a.n.lists.open-mesh.org-1; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org X-Mailman-Version: 3.2.1 Precedence: list Reply-To: The list for a Better Approach To Mobile Ad-hoc Networking List-Id: The list for a Better Approach To Mobile Ad-hoc Networking Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: From: Sven Eckelmann The batadv net_device is trying to propagate the needed_headroom and needed_tailroom from the lower devices. This is needed to avoid cost intensive reallocations using pskb_expand_head during the transmission. But the fragmentation code split the skb's without adding extra room at the end/beginning of the various fragments. This reduced the performance of transmissions over complex scenarios (batadv on vxlan on wireguard) because the lower devices had to perform the reallocations at least once. Fixes: ee75ed88879a ("batman-adv: Fragment and send skbs larger than mtu") Signed-off-by: Sven Eckelmann Signed-off-by: Simon Wunderlich --- net/batman-adv/fragmentation.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/net/batman-adv/fragmentation.c b/net/batman-adv/fragmentation.c index 9a47ef8b95c4..8de1fb567fd7 100644 --- a/net/batman-adv/fragmentation.c +++ b/net/batman-adv/fragmentation.c @@ -391,6 +391,7 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb, /** * batadv_frag_create() - create a fragment from skb + * @net_dev: outgoing device for fragment * @skb: skb to create fragment from * @frag_head: header to use in new fragment * @fragment_size: size of new fragment @@ -401,22 +402,25 @@ bool batadv_frag_skb_fwd(struct sk_buff *skb, * * Return: the new fragment, NULL on error. */ -static struct sk_buff *batadv_frag_create(struct sk_buff *skb, +static struct sk_buff *batadv_frag_create(struct net_device *net_dev, + struct sk_buff *skb, struct batadv_frag_packet *frag_head, unsigned int fragment_size) { + unsigned int ll_reserved = LL_RESERVED_SPACE(net_dev); + unsigned int tailroom = net_dev->needed_tailroom; struct sk_buff *skb_fragment; unsigned int header_size = sizeof(*frag_head); unsigned int mtu = fragment_size + header_size; - skb_fragment = netdev_alloc_skb(NULL, mtu + ETH_HLEN); + skb_fragment = dev_alloc_skb(ll_reserved + mtu + tailroom); if (!skb_fragment) goto err; skb_fragment->priority = skb->priority; /* Eat the last mtu-bytes of the skb */ - skb_reserve(skb_fragment, header_size + ETH_HLEN); + skb_reserve(skb_fragment, ll_reserved + header_size); skb_split(skb, skb_fragment, skb->len - fragment_size); /* Add the header */ @@ -439,11 +443,12 @@ int batadv_frag_send_packet(struct sk_buff *skb, struct batadv_orig_node *orig_node, struct batadv_neigh_node *neigh_node) { + struct net_device *net_dev = neigh_node->if_incoming->net_dev; struct batadv_priv *bat_priv; struct batadv_hard_iface *primary_if = NULL; struct batadv_frag_packet frag_header; struct sk_buff *skb_fragment; - unsigned int mtu = neigh_node->if_incoming->net_dev->mtu; + unsigned int mtu = net_dev->mtu; unsigned int header_size = sizeof(frag_header); unsigned int max_fragment_size, num_fragments; int ret; @@ -503,7 +508,7 @@ int batadv_frag_send_packet(struct sk_buff *skb, goto put_primary_if; } - skb_fragment = batadv_frag_create(skb, &frag_header, + skb_fragment = batadv_frag_create(net_dev, skb, &frag_header, max_fragment_size); if (!skb_fragment) { ret = -ENOMEM;