mirror of
https://github.com/torvalds/linux.git
synced 2026-08-01 03:59:40 +02:00
Linux kernel source tree
1fd6e56753
The byte queue limits (BQL) mechanism is intended to move queuing from the driver to the network stack in order to reduce latency caused by excessive queuing in hardware. However, when transmitting or redirecting a packet using generic XDP, the qdisc layer is bypassed and there are no additional queues. Since netif_xmit_stopped() also takes BQL limits into account, but without having any alternative queuing, packets are silently dropped. This patch modifies the drop condition to only consider cases when the driver itself cannot accept any more packets. This is analogous to the condition in __dev_direct_xmit(). Dropped packets are also counted on the device. Bypassing the qdisc layer in the generic XDP TX path means that XDP packets are able to starve other packets going through a qdisc, and DDOS attacks will be more effective. In-driver-XDP use dedicated TX queues, so they do not have this starvation issue. Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20220705082345.2494312-1-johan.almbladh@anyfinetworks.com |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.
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.