diff options
| -rw-r--r-- | include/linux/mm.h | 3 | ||||
| -rw-r--r-- | include/linux/rmap.h | 3 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 9 | ||||
| -rw-r--r-- | mm/interval_tree.c | 41 | ||||
| -rw-r--r-- | mm/mmap.c | 19 |
5 files changed, 64 insertions, 11 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 0cdab4e..0e6f9c9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1386,6 +1386,9 @@ struct anon_vma_chain *anon_vma_interval_tree_iter_first( struct rb_root *root, unsigned long start, unsigned long last); struct anon_vma_chain *anon_vma_interval_tree_iter_next( struct anon_vma_chain *node, unsigned long start, unsigned long last); +#ifdef CONFIG_DEBUG_VM_RB +void anon_vma_interval_tree_verify(struct anon_vma_chain *node); +#endif #define anon_vma_interval_tree_foreach(avc, root, start, last) \ for (avc = anon_vma_interval_tree_iter_first(root, start, last); \ diff --git a/include/linux/rmap.h b/include/linux/rmap.h index dce44f7..b2cce64 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -66,6 +66,9 @@ struct anon_vma_chain { struct list_head same_vma; /* locked by mmap_sem & page_table_lock */ struct rb_node rb; /* locked by anon_vma->mutex */ unsigned long rb_subtree_last; +#ifdef CONFIG_DEBUG_VM_RB + unsigned long cached_vma_start, cached_vma_last; +#endif }; #ifdef CONFIG_MMU diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a6e7e77..28e9d6c9 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -798,6 +798,15 @@ config DEBUG_VM If unsure, say N. +config DEBUG_VM_RB + bool "Debug VM red-black trees" + depends on DEBUG_VM + help + Enable this to turn on more extended checks in the virtual-memory + system that may impact performance. + + If unsure, say N. + config DEBUG_VIRTUAL bool "Debug VM translations" depends on DEBUG_KERNEL && X86 diff --git a/mm/interval_tree.c b/mm/interval_tree.c index f7c72cd..4a5822a 100644 --- a/mm/interval_tree.c +++ b/mm/interval_tree.c @@ -70,4 +70,43 @@ static inline unsigned long avc_last_pgoff(struct anon_vma_chain *avc) } INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last, - avc_start_pgoff, avc_last_pgoff,, anon_vma_interval_tree) + avc_start_pgoff, avc_last_pgoff, + static inline, __anon_vma_interval_tree) + +void anon_vma_interval_tree_insert(struct anon_vma_chain *node, + struct rb_root *root) +{ +#ifdef CONFIG_DEBUG_VM_RB + node->cached_vma_start = avc_start_pgoff(node); + node->cached_vma_last = avc_last_pgoff(node); +#endif + __anon_vma_interval_tree_insert(node, root); +} + +void anon_vma_interval_tree_remove(struct anon_vma_chain *node, + struct rb_root *root) +{ + __anon_vma_interval_tree_remove(node, root); +} + +struct anon_vma_chain * +anon_vma_interval_tree_iter_first(struct rb_root *root, + unsigned long first, unsigned long last) +{ + return __anon_vma_interval_tree_iter_first(root, first, last); +} + +struct anon_vma_chain * +anon_vma_interval_tree_iter_next(struct anon_vma_chain *node, + unsigned long first, unsigned long last) +{ + return __anon_vma_interval_tree_iter_next(node, first, last); +} + +#ifdef CONFIG_DEBUG_VM_RB +void anon_vma_interval_tree_verify(struct anon_vma_chain *node) +{ + WARN_ON_ONCE(node->cached_vma_start != avc_start_pgoff(node)); + WARN_ON_ONCE(node->cached_vma_last != avc_last_pgoff(node)); +} +#endif @@ -51,12 +51,6 @@ static void unmap_region(struct mm_struct *mm, struct vm_area_struct *vma, struct vm_area_struct *prev, unsigned long start, unsigned long end); -/* - * WARNING: the debugging will use recursive algorithms so never enable this - * unless you know what you are doing. - */ -#undef DEBUG_MM_RB - /* description of effects of mapping type and prot in current implementation. * this is due to the limited x86 page protection hardware. The expected * behavior is in parens: @@ -303,7 +297,7 @@ out: return retval; } -#ifdef DEBUG_MM_RB +#ifdef CONFIG_DEBUG_VM_RB static int browse_rb(struct rb_root *root) { int i = 0, j; @@ -337,9 +331,12 @@ void validate_mm(struct mm_struct *mm) { int bug = 0; int i = 0; - struct vm_area_struct *tmp = mm->mmap; - while (tmp) { - tmp = tmp->vm_next; + struct vm_area_struct *vma = mm->mmap; + while (vma) { + struct anon_vma_chain *avc; + list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) + anon_vma_interval_tree_verify(avc); + vma = vma->vm_next; i++; } if (i != mm->map_count) @@ -1790,6 +1787,7 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) } vma_unlock_anon_vma(vma); khugepaged_enter_vma_merge(vma); + validate_mm(vma->vm_mm); return error; } #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */ @@ -1843,6 +1841,7 @@ int expand_downwards(struct vm_area_struct *vma, } vma_unlock_anon_vma(vma); khugepaged_enter_vma_merge(vma); + validate_mm(vma->vm_mm); return error; } |