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