Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
a4ae997adc
This is meant to be a gentle introduction into the world of watermarks on ocelot. The code is placed in ocelot_devlink.c because it will be integrated with devlink, even if it isn't right now. My first step was intended to be to replicate the default configuration of the congestion watermarks programatically, since they are now going to be tuned by the user. But after studying and understanding through trial and error how they work, I now believe that the configuration used out of reset does not do justice to the word "reservation", since the sum of all reservations exceeds the total amount of resources (otherwise said, all reservations cannot be fulfilled at the same time, which means that, contrary to the reference manual, they don't guarantee anything). As an example, here's a dump of the reservation watermarks for frame buffers, for port 0 (for brevity, the ports 1-6 were omitted, but they have the same configuration): BUF_Q_RSRV_I(port 0, prio 0) = max 3000 bytes BUF_Q_RSRV_I(port 0, prio 1) = max 3000 bytes BUF_Q_RSRV_I(port 0, prio 2) = max 3000 bytes BUF_Q_RSRV_I(port 0, prio 3) = max 3000 bytes BUF_Q_RSRV_I(port 0, prio 4) = max 3000 bytes BUF_Q_RSRV_I(port 0, prio 5) = max 3000 bytes BUF_Q_RSRV_I(port 0, prio 6) = max 3000 bytes BUF_Q_RSRV_I(port 0, prio 7) = max 3000 bytes Otherwise said, every port-tc has an ingress reservation of 3000 bytes, and there are 7 ports in VSC9959 Felix (6 user ports and 1 CPU port). Concentrating only on the ingress reservations, there are, in total, 8 [traffic classes] x 7 [ports] x 3000 [bytes] = 168,000 bytes of memory reserved on ingress. But, surprise, Felix only has 128 KB of packet buffer in total... A similar thing happens with Seville, which has a larger packet buffer, but also more ports, and the default configuration is also overcommitted. This patch disables the (apparently) bogus reservations and moves all resources to the shared area. This way, real reservations can be set up by the user, using devlink-sb. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
||
|---|---|---|
| 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.