76d62f24db
Wei Wang reported seeing priority inversion caused latencies caused by contention on pmsg_lock, and suggested it be switched to a rt_mutex. I was initially hesitant this would help, as the tasks in that trace all seemed to be SCHED_NORMAL, so the benefit would be limited to only nice boosting. However, another similar issue was raised where the priority inversion was seen did involve a blocked RT task so it is clear this would be helpful in that case. Cc: Wei Wang <wvw@google.com> Cc: Midas Chien<midaschieh@google.com> Cc: Connor O'Brien <connoro@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Cc: kernel-team@android.com Fixes: 9d5438f462ab ("pstore: Add pmsg - user-space accessible pstore object") Reported-by: Wei Wang <wvw@google.com> Signed-off-by: John Stultz <jstultz@google.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20221214231834.3711880-1-jstultz@google.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.