mainlining shenanigans
d5b59a7120
On parisc we want to be as much as possible compatible to the major architectures like x86. Those architectures have MAP_TYPE defined as 0x0f which covers MAP_SHARED and MAP_PRIVATE and leaves two more bits unused. In contrast, on parisc we have MAP_TYPE defined to 0x03 which covers MAP_SHARED and MAP_PRIVATE only. But we don't have the 2 bits free as x86. Usually that's not a problem, but during the discussions for pmem+dax support the idea came up to use the two remaining bits of MAP_TYPE (on x86 and others) for the new MAP_DIRECT and MAP_SYNC flags. One requirement is, that an old kernel should correctly handle MAP_DIRECT and MAP_SYNC and fail on those if set. This only works if MAP_TYPE has 4 bits. Even though the pmem+dax people now choosed another solution via MAP_SHARED_VALIDATE, let's still proceed to be more compatible to x86 by adding two more bits for future usage. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: John David Anglin <dave.anglin@bell.net> |
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| kernel | ||
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| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.