83bc4ec372
Searching for an available hole by address is slow, as there no guarantee that a hole will be available and so we must walk over all nodes in the rbtree before we determine the search was futile. In many cases, the caller doesn't strictly care for the highest available hole and was just opportunistically laying out the address space in a preferred order. In such cases, the caller can accept any address and would rather do so then do a slow walk. To be able to mix search strategies, the caller wants to tell the drm_mm how long to spend on the search. Without a good guide for what should be the best split, start with a request to try once at most. That is return the top-most (or lowest) hole if it fulfils the alignment and size requirements. v2: Documentation, by why of example (selftests) and kerneldoc. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20180521082131.13744-2-chris@chris-wilson.co.uk
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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.