9030e39cd1
Some selftests assume that nothing will attempt to grab these bitlocks while they are held by the selftests. With GuC, for example, that is not true because the hanging workloads may cause the GuC code to attempt to grab them for a global reset, and that may cause it to end up sleeping on the bit never waking up. Regardless whether that will be the final solution for GuC, use clear_and_wake_up_bit() pending a more thorough investigation on how this should be handled moving forward. To be clear this needs to be a temporary solution. If we can't find an in-kernel locking primitive to use here, we should at the very least add lockdep annotation to these bitlocks with a thorough explanation as to why we need to use bits. v3: - Use GEM_BUG_ON(test_and_set_bit()) rather than set_bit() to verify the assumption that nothing is holding the reset locks when we attempt to grab them. (Chris Wilson) Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20211105150146.834052-1-thomas.hellstrom@linux.intel.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.