98102a2cb7
At present fp-stress has a bit of a thundering herd problem since the children it spawns start running immediately, meaning that they can start starving the parent process of CPU before it has even started all the children. This is much more severe on virtual platforms since they tend to support far more SVE and SME vector lengths, be slower in general and for some have issues with performance when simulating multiple CPUs. We can mitigate this problem by having all the child processes block before starting the test program, meaning that we at least have all the child processes started before we start heavily using CPU. We still have the same load issues while waiting for the actual stress test programs to start up and produce output but they're at least all ready to go before that kicks in, resulting in substantial reductions in overall runtime on some of the severely affected systems. One test was showing about 20% improvement. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20221129215926.442895-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
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.