From: Jakub Kicinski <kuba@kernel.org>
To: Sven Eckelmann <sven@narfation.org>
Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org,
linux-kernel@vger.kernel.org,
Annika Wickert <annika.wickert@exaring.de>
Subject: Re: [PATCH 1/2] vxlan: Add needed_headroom for lower device
Date: Mon, 30 Nov 2020 18:34:25 -0800 [thread overview]
Message-ID: <20201130183425.7086ae00@kicinski-fedora-pc1c0hjn.DHCP.thefacebook.com> (raw)
In-Reply-To: <20201126125247.1047977-1-sven@narfation.org>
On Thu, 26 Nov 2020 13:52:46 +0100 Sven Eckelmann wrote:
> It was observed that sending data via batadv over vxlan (on top of
> wireguard) reduced the performance massively compared to raw ethernet or
> batadv on raw ethernet. A check of perf data showed that the
> vxlan_build_skb was calling all the time pskb_expand_head to allocate
> enough headroom for:
>
> min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len
> + VXLAN_HLEN + iphdr_len;
>
> But the vxlan_config_apply only requested needed headroom for:
>
> lowerdev->hard_header_len + VXLAN6_HEADROOM or VXLAN_HEADROOM
>
> So it completely ignored the needed_headroom of the lower device. The first
> caller of net_dev_xmit could therefore never make sure that enough headroom
> was allocated for the rest of the transmit path.
>
> Cc: Annika Wickert <annika.wickert@exaring.de>
> Signed-off-by: Sven Eckelmann <sven@narfation.org>
Applied both, thanks!
prev parent reply other threads:[~2020-12-01 2:35 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-26 12:52 [PATCH 1/2] vxlan: Add needed_headroom for lower device Sven Eckelmann
2020-11-26 12:52 ` [PATCH 2/2] vxlan: Copy needed_tailroom from lowerdev Sven Eckelmann
2020-11-26 18:19 ` [PATCH 1/2] vxlan: Add needed_headroom for lower device Annika Wickert
2020-12-01 2:34 ` Jakub Kicinski [this message]
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