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cca10df102
Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by using bit 6 in the PTE, reducing the swap type in the !CONFIG_X2TLB case to 5 bits. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. Interrestingly, the swap type in the !CONFIG_X2TLB case could currently overlap with the _PAGE_PRESENT bit, because there is a sneaky shift by 1 in __pte_to_swp_entry() and __swp_entry_to_pte(). Bit 0-7 in the architecture specific swap PTE would get shifted to bit 1-8 in the PTE. As generic MM uses 5 bits only, this didn't matter so far. While at it, mask the type in __swp_entry(). Link: https://lkml.kernel.org/r/20230113171026.582290-21-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.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.