This macro adds some debug code to check that the augment tree is maintained correctly, meaning that every node contains valid subtree_max_size value. By default this option is set to 0 and not active. It requires recompilation of the kernel to activate it. Set to 1, compile the kernel. [urezki@gmail.com: v4] Link: http://lkml.kernel.org/r/20190406183508.25273-3-urezki@gmail.com Link: http://lkml.kernel.org/r/20190402162531.10888-3-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Roman Gushchin <guro@fb.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Joel Fernandes <joelaf@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Unified · Split
| @@ -325,6 +325,8 @@ EXPORT_SYMBOL(vmalloc_to_pfn); · 324 unmodified lines | ||
| 325 | 325 | |
| 326 | 326 | /*** Global kva allocator ***/ |
| 327 | 327 | |
| 328 | +#define DEBUG_AUGMENT_PROPAGATE_CHECK 0 | |
| 329 | + | |
| 328 | 330 | #define VM_LAZY_FREE 0x02 |
| 329 | 331 | #define VM_VM_AREA 0x04 |
| 330 | 332 | |
| @@ -539,6 +541,48 @@ unlink_va(struct vmap_area *va, struct rb_root *root) · 208 unmodified lines | ||
| 539 | 541 | } |
| 540 | 542 | } |
| 541 | 543 | |
| 544 | +#if DEBUG_AUGMENT_PROPAGATE_CHECK | |
| 545 | +static void | |
| 546 | +augment_tree_propagate_check(struct rb_node *n) | |
| 547 | +{ | |
| 548 | + struct vmap_area *va; | |
| 549 | + struct rb_node *node; | |
| 550 | + unsigned long size; | |
| 551 | + bool found = false; | |
| 552 | + | |
| 553 | + if (n == NULL) | |
| 554 | + return; | |
| 555 | + | |
| 556 | + va = rb_entry(n, struct vmap_area, rb_node); | |
| 557 | + size = va->subtree_max_size; | |
| 558 | + node = n; | |
| 559 | + | |
| 560 | + while (node) { | |
| 561 | + va = rb_entry(node, struct vmap_area, rb_node); | |
| 562 | + | |
| 563 | + if (get_subtree_max_size(node->rb_left) == size) { | |
| 564 | + node = node->rb_left; | |
| 565 | + } else { | |
| 566 | + if (va_size(va) == size) { | |
| 567 | + found = true; | |
| 568 | + break; | |
| 569 | + } | |
| 570 | + | |
| 571 | + node = node->rb_right; | |
| 572 | + } | |
| 573 | + } | |
| 574 | + | |
| 575 | + if (!found) { | |
| 576 | + va = rb_entry(n, struct vmap_area, rb_node); | |
| 577 | + pr_emerg("tree is corrupted: %lu, %lu\n", | |
| 578 | + va_size(va), va->subtree_max_size); | |
| 579 | + } | |
| 580 | + | |
| 581 | + augment_tree_propagate_check(n->rb_left); | |
| 582 | + augment_tree_propagate_check(n->rb_right); | |
| 583 | +} | |
| 584 | +#endif | |
| 585 | + | |
| 542 | 586 | /* |
| 543 | 587 | * This function populates subtree_max_size from bottom to upper |
| 544 | 588 | * levels starting from VA point. The propagation must be done |
| @@ -588,6 +632,10 @@ augment_tree_propagate_from(struct vmap_area *va) · 43 unmodified lines | ||
| 588 | 632 | va->subtree_max_size = new_va_sub_max_size; |
| 589 | 633 | node = rb_parent(&va->rb_node); |
| 590 | 634 | } |
| 635 | + | |
| 636 | +#if DEBUG_AUGMENT_PROPAGATE_CHECK | |
| 637 | + augment_tree_propagate_check(free_vmap_area_root.rb_node); | |
| 638 | +#endif | |
| 591 | 639 | } |
| 592 | 640 | |
| 593 | 641 | static void |