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295b6c02f8
Currently the FE is spinning way too fast when polling for new work in the FE idleloop. As each poll fetches 16 bytes from memory, a GPU running at 1GHz with the current setting of 200 wait cycle between fetches causes 80 MB/s of memory traffic just to check for new work when the GPU is otherwise idle, which is more FE traffic than in some GPU loaded cases. Significantly increase the number of wait cycles to slow down the poll interval to ~30µs, limiting the FE idle memory traffic to 512 KB/s, while providing a max latency which should not hurt most use-cases. The FE WAIT command seems to have some unknown discrete steps in the wait cycles so we may over/undershoot the target a bit, but that should be harmless. If the GPU core base frequency is unknown keep the 200 wait cycles as a sane default. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn> Tested-by: Sui Jingfeng <suijingfeng@loongson.cn> Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
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.