linux-stable/net/mpls
Christoph Paasch 8edbd39601 mpls: Do not orphan the skb
We observed that TCP-pacing was falling back to the TCP-layer pacing
instead of utilizing sch_fq for the pacing. This causes significant
CPU-usage due to the hrtimer running on a per-TCP-connection basis.

The issue is that mpls_xmit() calls skb_orphan() and thus sets
skb->sk to NULL. Which implies that many of the goodies of TCP won't
work. Pacing falls back to TCP-layer pacing. TCP Small Queues does not
work, ...

It is safe to remove this call to skb_orphan() in mpls_xmit() as there
really is not reason for it to be there. It appears that this call to
skb_orphan comes from the very initial implementation of MPLS.

Cc: Roopa Prabhu <roopa@nvidia.com>
Reported-by: Craig Taylor <cmtaylor@apple.com>
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Link: https://lore.kernel.org/r/20240306181117.77419-1-cpaasch@apple.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-07 20:42:13 -08:00
..
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
af_mpls.c inet: allow ip_valid_fib_dump_req() to be called with RTNL or RCU 2024-02-26 11:46:12 +00:00
internal.h Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-02 11:44:56 -08:00
mpls_gso.c net: mpls: error out if inner headers are not set 2024-02-23 16:22:56 -08:00
mpls_iptunnel.c mpls: Do not orphan the skb 2024-03-07 20:42:13 -08:00