diff options
| -rw-r--r-- | mm/Kconfig.debug | 18 | ||||
| -rw-r--r-- | mm/page_alloc.c | 6 |
2 files changed, 21 insertions, 3 deletions
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug index 957d3da53ddd..a0c136af9c91 100644 --- a/mm/Kconfig.debug +++ b/mm/Kconfig.debug @@ -16,8 +16,8 @@ config DEBUG_PAGEALLOC select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC ---help--- Unmap pages from the kernel linear mapping after free_pages(). - This results in a large slowdown, but helps to find certain types - of memory corruption. + 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 @@ -26,5 +26,19 @@ config DEBUG_PAGEALLOC 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 diff --git a/mm/page_alloc.c b/mm/page_alloc.c index fe4378fc0ab6..36a0a792f4f8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -478,7 +478,8 @@ void prep_compound_page(struct page *page, unsigned int order) #ifdef CONFIG_DEBUG_PAGEALLOC unsigned int _debug_guardpage_minorder; -bool _debug_pagealloc_enabled __read_mostly; +bool _debug_pagealloc_enabled __read_mostly + = IS_ENABLED(CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT); bool _debug_guardpage_enabled __read_mostly; static int __init early_debug_pagealloc(char *buf) @@ -489,6 +490,9 @@ static int __init early_debug_pagealloc(char *buf) if (strcmp(buf, "on") == 0) _debug_pagealloc_enabled = true; + if (strcmp(buf, "off") == 0) + _debug_pagealloc_enabled = false; + return 0; } early_param("debug_pagealloc", early_debug_pagealloc); |