45 lines
1.8 KiB
Plaintext
45 lines
1.8 KiB
Plaintext
config PAGE_EXTENSION
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bool "Extend memmap on extra space for more information on page"
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---help---
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Extend memmap on extra space for more information on page. This
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could be used for debugging features that need to insert extra
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field for every page. This extension enables us to save memory
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by not allocating this extra memory according to boottime
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configuration.
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config DEBUG_PAGEALLOC
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bool "Debug page memory allocations"
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depends on DEBUG_KERNEL
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depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
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depends on !KMEMCHECK
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select PAGE_EXTENSION
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select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
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---help---
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Unmap pages from the kernel linear mapping after free_pages().
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Depending on runtime enablement, this results in a small or large
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slowdown, but helps to find certain types of memory corruption.
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For architectures which don't enable ARCH_SUPPORTS_DEBUG_PAGEALLOC,
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fill the pages with poison patterns after free_pages() and verify
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the patterns before alloc_pages(). Additionally,
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this option cannot be enabled in combination with hibernation as
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that would result in incorrect warnings of memory corruption after
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a resume because free pages are not saved to the suspend image.
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By default this option will have a small overhead, e.g. by not
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allowing the kernel mapping to be backed by large pages on some
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architectures. Even bigger overhead comes when the debugging is
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enabled by DEBUG_PAGEALLOC_ENABLE_DEFAULT or the debug_pagealloc
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command line parameter.
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config DEBUG_PAGEALLOC_ENABLE_DEFAULT
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bool "Enable debug page memory allocations by default?"
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default n
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depends on DEBUG_PAGEALLOC
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---help---
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Enable debug page memory allocations by default? This value
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can be overridden by debug_pagealloc=off|on.
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config PAGE_POISONING
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bool
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