mirror of https://gitee.com/openkylin/linux.git
4cd071d13c
Move the calls to thp_adjust() down a level from the page fault handlers to the map/fetch helpers and remove the page count shuffling done in thp_adjust(). Despite holding a reference to the underlying page while processing a page fault, the page fault flows don't actually rely on holding a reference to the page when thp_adjust() is called. At that point, the fault handlers hold mmu_lock, which prevents mmu_notifier from completing any invalidations, and have verified no invalidations from mmu_notifier have occurred since the page reference was acquired (which is done prior to taking mmu_lock). The kvm_release_pfn_clean()/kvm_get_pfn() dance in thp_adjust() is a quirk that is necessitated because thp_adjust() modifies the pfn that is consumed by its caller. Because the page fault handlers call kvm_release_pfn_clean() on said pfn, thp_adjust() needs to transfer the reference to the correct pfn purely for correctness when the pfn is released. Calling thp_adjust() from __direct_map() and FNAME(fetch) means the pfn adjustment doesn't change the pfn as seen by the page fault handlers, i.e. the pfn released by the page fault handlers is the same pfn that was returned by gfn_to_pfn(). Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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| fs | ||
| include | ||
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| kernel | ||
| lib | ||
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| samples | ||
| scripts | ||
| security | ||
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| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
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| README | ||
README
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.