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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sven Eckelmann <sven@narfation.org>,
	Annika Wickert <annika.wickert@exaring.de>,
	Annika Wickert <aw@awlnx.space>, Jakub Kicinski <kuba@kernel.org>,
	Sasha Levin <sashal@kernel.org>,
	netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 06/14] vxlan: Add needed_headroom for lower device
Date: Sat, 12 Dec 2020 11:08:23 -0500	[thread overview]
Message-ID: <20201212160831.2335172-6-sashal@kernel.org> (raw)
In-Reply-To: <20201212160831.2335172-1-sashal@kernel.org>

From: Sven Eckelmann <sven@narfation.org>

[ Upstream commit 0a35dc41fea67ac4495ce7584406bf9557a6e7d0 ]

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>
---
 drivers/net/vxlan.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 630ac00a34ede..3753cf0942865 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -3538,6 +3538,7 @@ static void vxlan_config_apply(struct net_device *dev,
 		dev->gso_max_segs = lowerdev->gso_max_segs;
 
 		needed_headroom = lowerdev->hard_header_len;
+		needed_headroom += lowerdev->needed_headroom;
 
 		max_mtu = lowerdev->mtu - (use_ipv6 ? VXLAN6_HEADROOM :
 					   VXLAN_HEADROOM);
-- 
2.27.0


  parent reply	other threads:[~2020-12-12 16:29 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-12 16:08 [PATCH AUTOSEL 5.4 01/14] drm/tegra: replace idr_init() by idr_init_base() Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 02/14] kernel/cpu: add arch override for clear_tasks_mm_cpumask() mm handling Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 03/14] drm/tegra: sor: Disable clocks on error in tegra_sor_init() Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 04/14] habanalabs: put devices before driver removal Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 05/14] arm64: syscall: exit userspace before unmasking exceptions Sasha Levin
2020-12-12 16:08 ` Sasha Levin [this message]
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 07/14] vxlan: Copy needed_tailroom from lowerdev Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 08/14] scsi: storvsc: Validate length of incoming packet in storvsc_on_channel_callback() Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 09/14] scsi: mpt3sas: Increase IOCInit request timeout to 30s Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 10/14] dm table: Remove BUG_ON(in_interrupt()) Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 11/14] iwlwifi: pcie: add one missing entry for AX210 Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 12/14] drm/amd/display: Init clock value by current vbios CLKs Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 13/14] perf/x86/intel: Check PEBS status correctly Sasha Levin
2020-12-12 16:08 ` [PATCH AUTOSEL 5.4 14/14] kbuild: avoid split lines in .mod files Sasha Levin

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