diff options
| -rw-r--r-- | include/linux/mm.h | 14 | ||||
| -rw-r--r-- | include/linux/rmap.h | 11 | ||||
| -rw-r--r-- | mm/huge_memory.c | 5 | ||||
| -rw-r--r-- | mm/interval_tree.c | 14 | ||||
| -rw-r--r-- | mm/ksm.c | 9 | ||||
| -rw-r--r-- | mm/memory-failure.c | 5 | ||||
| -rw-r--r-- | mm/mmap.c | 73 | ||||
| -rw-r--r-- | mm/rmap.c | 24 |
8 files changed, 114 insertions, 41 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index f1d9aaa..0cdab4e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -20,6 +20,7 @@ struct mempolicy; struct anon_vma; +struct anon_vma_chain; struct file_ra_state; struct user_struct; struct writeback_control; @@ -1377,6 +1378,19 @@ static inline void vma_nonlinear_insert(struct vm_area_struct *vma, list_add_tail(&vma->shared.nonlinear, list); } +void anon_vma_interval_tree_insert(struct anon_vma_chain *node, + struct rb_root *root); +void anon_vma_interval_tree_remove(struct anon_vma_chain *node, + struct rb_root *root); +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); + +#define anon_vma_interval_tree_foreach(avc, root, start, last) \ + for (avc = anon_vma_interval_tree_iter_first(root, start, last); \ + avc; avc = anon_vma_interval_tree_iter_next(avc, start, last)) + /* mmap.c */ extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin); extern int vma_adjust(struct vm_area_struct *vma, unsigned long start, diff --git a/include/linux/rmap.h b/include/linux/rmap.h index 7f32cec..dce44f7 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -37,14 +37,14 @@ struct anon_vma { atomic_t refcount; /* - * NOTE: the LSB of the head.next is set by + * NOTE: the LSB of the rb_root.rb_node is set by * mm_take_all_locks() _after_ taking the above lock. So the - * head must only be read/written after taking the above lock + * rb_root must only be read/written after taking the above lock * to be sure to see a valid next pointer. The LSB bit itself * is serialized by a system wide lock only visible to * mm_take_all_locks() (mm_all_locks_mutex). */ - struct list_head head; /* Chain of private "related" vmas */ + struct rb_root rb_root; /* Interval tree of private "related" vmas */ }; /* @@ -57,14 +57,15 @@ struct anon_vma { * with a VMA, or the VMAs associated with an anon_vma. * The "same_vma" list contains the anon_vma_chains linking * all the anon_vmas associated with this VMA. - * The "same_anon_vma" list contains the anon_vma_chains + * The "rb" field indexes on an interval tree the anon_vma_chains * which link all the VMAs associated with this anon_vma. */ struct anon_vma_chain { struct vm_area_struct *vma; struct anon_vma *anon_vma; struct list_head same_vma; /* locked by mmap_sem & page_table_lock */ - struct list_head same_anon_vma; /* locked by anon_vma->mutex */ + struct rb_node rb; /* locked by anon_vma->mutex */ + unsigned long rb_subtree_last; }; #ifdef CONFIG_MMU diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 010d329..ce59ada 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1375,13 +1375,14 @@ static void __split_huge_page(struct page *page, struct anon_vma *anon_vma) { int mapcount, mapcount2; + pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); struct anon_vma_chain *avc; BUG_ON(!PageHead(page)); BUG_ON(PageTail(page)); mapcount = 0; - list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long addr = vma_address(page, vma); BUG_ON(is_vma_temporary_stack(vma)); @@ -1407,7 +1408,7 @@ static void __split_huge_page(struct page *page, __split_huge_page_refcount(page); mapcount2 = 0; - list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long addr = vma_address(page, vma); BUG_ON(is_vma_temporary_stack(vma)); diff --git a/mm/interval_tree.c b/mm/interval_tree.c index 4ab7b9e..f7c72cd 100644 --- a/mm/interval_tree.c +++ b/mm/interval_tree.c @@ -8,6 +8,7 @@ #include <linux/mm.h> #include <linux/fs.h> +#include <linux/rmap.h> #include <linux/interval_tree_generic.h> static inline unsigned long vma_start_pgoff(struct vm_area_struct *v) @@ -57,3 +58,16 @@ void vma_interval_tree_insert_after(struct vm_area_struct *node, rb_insert_augmented(&node->shared.linear.rb, root, &vma_interval_tree_augment); } + +static inline unsigned long avc_start_pgoff(struct anon_vma_chain *avc) +{ + return vma_start_pgoff(avc->vma); +} + +static inline unsigned long avc_last_pgoff(struct anon_vma_chain *avc) +{ + return vma_last_pgoff(avc->vma); +} + +INTERVAL_TREE_DEFINE(struct anon_vma_chain, rb, unsigned long, rb_subtree_last, + avc_start_pgoff, avc_last_pgoff,, anon_vma_interval_tree) @@ -1618,7 +1618,8 @@ again: struct vm_area_struct *vma; anon_vma_lock(anon_vma); - list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, + 0, ULONG_MAX) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || rmap_item->address >= vma->vm_end) @@ -1671,7 +1672,8 @@ again: struct vm_area_struct *vma; anon_vma_lock(anon_vma); - list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, + 0, ULONG_MAX) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || rmap_item->address >= vma->vm_end) @@ -1723,7 +1725,8 @@ again: struct vm_area_struct *vma; anon_vma_lock(anon_vma); - list_for_each_entry(vmac, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, + 0, ULONG_MAX) { vma = vmac->vma; if (rmap_item->address < vma->vm_start || rmap_item->address >= vma->vm_end) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index c38a625..6c5899b 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -400,18 +400,21 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill, struct vm_area_struct *vma; struct task_struct *tsk; struct anon_vma *av; + pgoff_t pgoff; av = page_lock_anon_vma(page); if (av == NULL) /* Not actually mapped anymore */ return; + pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); read_lock(&tasklist_lock); for_each_process (tsk) { struct anon_vma_chain *vmac; if (!task_early_kill(tsk)) continue; - list_for_each_entry(vmac, &av->head, same_anon_vma) { + anon_vma_interval_tree_foreach(vmac, &av->rb_root, + pgoff, pgoff) { vma = vmac->vma; if (!page_mapped_in_vma(page, vma)) continue; @@ -353,6 +353,38 @@ void validate_mm(struct mm_struct *mm) #define validate_mm(mm) do { } while (0) #endif +/* + * vma has some anon_vma assigned, and is already inserted on that + * anon_vma's interval trees. + * + * Before updating the vma's vm_start / vm_end / vm_pgoff fields, the + * vma must be removed from the anon_vma's interval trees using + * anon_vma_interval_tree_pre_update_vma(). + * + * After the update, the vma will be reinserted using + * anon_vma_interval_tree_post_update_vma(). + * + * The entire update must be protected by exclusive mmap_sem and by + * the root anon_vma's mutex. + */ +static inline void +anon_vma_interval_tree_pre_update_vma(struct vm_area_struct *vma) +{ + struct anon_vma_chain *avc; + + list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) + anon_vma_interval_tree_remove(avc, &avc->anon_vma->rb_root); +} + +static inline void +anon_vma_interval_tree_post_update_vma(struct vm_area_struct *vma) +{ + struct anon_vma_chain *avc; + + list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) + anon_vma_interval_tree_insert(avc, &avc->anon_vma->rb_root); +} + static int find_vma_links(struct mm_struct *mm, unsigned long addr, unsigned long end, struct vm_area_struct **pprev, struct rb_node ***rb_link, struct rb_node **rb_parent) @@ -565,20 +597,17 @@ again: remove_next = 1 + (end > next->vm_end); vma_adjust_trans_huge(vma, start, end, adjust_next); - /* - * When changing only vma->vm_end, we don't really need anon_vma - * lock. This is a fairly rare case by itself, but the anon_vma - * lock may be shared between many sibling processes. Skipping - * the lock for brk adjustments makes a difference sometimes. - */ - if (vma->anon_vma && (importer || start != vma->vm_start)) { - anon_vma = vma->anon_vma; + anon_vma = vma->anon_vma; + if (!anon_vma && adjust_next) + anon_vma = next->anon_vma; + if (anon_vma) { VM_BUG_ON(adjust_next && next->anon_vma && anon_vma != next->anon_vma); - } else if (adjust_next && next->anon_vma) - anon_vma = next->anon_vma; - if (anon_vma) anon_vma_lock(anon_vma); + anon_vma_interval_tree_pre_update_vma(vma); + if (adjust_next) + anon_vma_interval_tree_pre_update_vma(next); + } if (root) { flush_dcache_mmap_lock(mapping); @@ -619,8 +648,12 @@ again: remove_next = 1 + (end > next->vm_end); __insert_vm_struct(mm, insert); } - if (anon_vma) + if (anon_vma) { + anon_vma_interval_tree_post_update_vma(vma); + if (adjust_next) + anon_vma_interval_tree_post_update_vma(next); anon_vma_unlock(anon_vma); + } if (mapping) mutex_unlock(&mapping->i_mmap_mutex); @@ -1748,7 +1781,9 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address) if (vma->vm_pgoff + (size >> PAGE_SHIFT) >= vma->vm_pgoff) { error = acct_stack_growth(vma, size, grow); if (!error) { + anon_vma_interval_tree_pre_update_vma(vma); vma->vm_end = address; + anon_vma_interval_tree_post_update_vma(vma); perf_event_mmap(vma); } } @@ -1798,8 +1833,10 @@ int expand_downwards(struct vm_area_struct *vma, if (grow <= vma->vm_pgoff) { error = acct_stack_growth(vma, size, grow); if (!error) { + anon_vma_interval_tree_pre_update_vma(vma); vma->vm_start = address; vma->vm_pgoff -= grow; + anon_vma_interval_tree_post_update_vma(vma); perf_event_mmap(vma); } } @@ -2515,7 +2552,7 @@ static DEFINE_MUTEX(mm_all_locks_mutex); static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) { - if (!test_bit(0, (unsigned long *) &anon_vma->root->head.next)) { + if (!test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_node)) { /* * The LSB of head.next can't change from under us * because we hold the mm_all_locks_mutex. @@ -2531,7 +2568,7 @@ static void vm_lock_anon_vma(struct mm_struct *mm, struct anon_vma *anon_vma) * anon_vma->root->mutex. */ if (__test_and_set_bit(0, (unsigned long *) - &anon_vma->root->head.next)) + &anon_vma->root->rb_root.rb_node)) BUG(); } } @@ -2572,7 +2609,7 @@ static void vm_lock_mapping(struct mm_struct *mm, struct address_space *mapping) * A single task can't take more than one mm_take_all_locks() in a row * or it would deadlock. * - * The LSB in anon_vma->head.next and the AS_MM_ALL_LOCKS bitflag in + * The LSB in anon_vma->rb_root.rb_node and the AS_MM_ALL_LOCKS bitflag in * mapping->flags avoid to take the same lock twice, if more than one * vma in this mm is backed by the same anon_vma or address_space. * @@ -2619,13 +2656,13 @@ out_unlock: static void vm_unlock_anon_vma(struct anon_vma *anon_vma) { - if (test_bit(0, (unsigned long *) &anon_vma->root->head.next)) { + if (test_bit(0, (unsigned long *) &anon_vma->root->rb_root.rb_node)) { /* * The LSB of head.next can't change to 0 from under * us because we hold the mm_all_locks_mutex. * * We must however clear the bitflag before unlocking - * the vma so the users using the anon_vma->head will + * the vma so the users using the anon_vma->rb_root will * never see our bitflag. * * No need of atomic instructions here, head.next @@ -2633,7 +2670,7 @@ static void vm_unlock_anon_vma(struct anon_vma *anon_vma) * anon_vma->root->mutex. */ if (!__test_and_clear_bit(0, (unsigned long *) - &anon_vma->root->head.next)) + &anon_vma->root->rb_root.rb_node)) BUG(); anon_vma_unlock(anon_vma); } @@ -127,12 +127,7 @@ static void anon_vma_chain_link(struct vm_area_struct *vma, avc->vma = vma; avc->anon_vma = anon_vma; list_add(&avc->same_vma, &vma->anon_vma_chain); - - /* - * It's critical to add new vmas to the tail of the anon_vma, - * see comment in huge_memory.c:__split_huge_page(). - */ - list_add_tail(&avc->same_anon_vma, &anon_vma->head); + anon_vma_interval_tree_insert(avc, &anon_vma->rb_root); } /** @@ -336,13 +331,13 @@ void unlink_anon_vmas(struct vm_area_struct *vma) struct anon_vma *anon_vma = avc->anon_vma; root = lock_anon_vma_root(root, anon_vma); - list_del(&avc->same_anon_vma); + anon_vma_interval_tree_remove(avc, &anon_vma->rb_root); /* * Leave empty anon_vmas on the list - we'll need * to free them outside the lock. */ - if (list_empty(&anon_vma->head)) + if (RB_EMPTY_ROOT(&anon_vma->rb_root)) continue; list_del(&avc->same_vma); @@ -371,7 +366,7 @@ static void anon_vma_ctor(void *data) mutex_init(&anon_vma->mutex); atomic_set(&anon_vma->refcount, 0); - INIT_LIST_HEAD(&anon_vma->head); + anon_vma->rb_root = RB_ROOT; } void __init anon_vma_init(void) @@ -724,6 +719,7 @@ static int page_referenced_anon(struct page *page, { unsigned int mapcount; struct anon_vma *anon_vma; + pgoff_t pgoff; struct anon_vma_chain *avc; int referenced = 0; @@ -732,7 +728,8 @@ static int page_referenced_anon(struct page *page, return referenced; mapcount = page_mapcount(page); - list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { + pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); + anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long address = vma_address(page, vma); if (address == -EFAULT) @@ -1445,6 +1442,7 @@ bool is_vma_temporary_stack(struct vm_area_struct *vma) static int try_to_unmap_anon(struct page *page, enum ttu_flags flags) { struct anon_vma *anon_vma; + pgoff_t pgoff; struct anon_vma_chain *avc; int ret = SWAP_AGAIN; @@ -1452,7 +1450,8 @@ static int try_to_unmap_anon(struct page *page, enum ttu_flags flags) if (!anon_vma) return ret; - list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { + pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); + anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long address; @@ -1668,6 +1667,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, struct vm_area_struct *, unsigned long, void *), void *arg) { struct anon_vma *anon_vma; + pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT); struct anon_vma_chain *avc; int ret = SWAP_AGAIN; @@ -1681,7 +1681,7 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *, if (!anon_vma) return ret; anon_vma_lock(anon_vma); - list_for_each_entry(avc, &anon_vma->head, same_anon_vma) { + anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) { struct vm_area_struct *vma = avc->vma; unsigned long address = vma_address(page, vma); if (address == -EFAULT) |
