mirror of
https://github.com/hardkernel/linux.git
synced 2026-06-08 03:40:35 +09:00
bf187ef6e1
[ Upstream commit 0a35dc41fe ]
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>
Tested-by: Annika Wickert <aw@awlnx.space>
Link: https://lore.kernel.org/r/20201126125247.1047977-1-sven@narfation.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.