From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx116.postini.com [74.125.245.116]) by kanga.kvack.org (Postfix) with SMTP id B767B6B006E for ; Wed, 31 Oct 2012 06:33:41 -0400 (EDT) Received: by mail-pb0-f41.google.com with SMTP id rq2so971403pbb.14 for ; Wed, 31 Oct 2012 03:33:41 -0700 (PDT) From: Michel Lespinasse Subject: [RFC PATCH 2/6] mm: check rb_subtree_gap correctness Date: Wed, 31 Oct 2012 03:33:21 -0700 Message-Id: <1351679605-4816-3-git-send-email-walken@google.com> In-Reply-To: <1351679605-4816-1-git-send-email-walken@google.com> References: <1351679605-4816-1-git-send-email-walken@google.com> Sender: owner-linux-mm@kvack.org List-ID: To: Rik van Riel , Hugh Dickins , Mel Gorman , Peter Zijlstra , Johannes Weiner , Andrea Arcangeli Cc: linux-mm@kvack.org When CONFIG_DEBUG_VM_RB is enabled, check that rb_subtree_gap is correctly set for every vma and that mm->highest_vm_end is also correct. Also add an explicit 'bug' variable to track if browse_rb() detected any invalid condition. Signed-off-by: Michel Lespinasse --- mm/mmap.c | 24 ++++++++++++++++-------- 1 files changed, 16 insertions(+), 8 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 4b14c4070305..548fed471398 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -365,7 +365,7 @@ static void vma_rb_erase(struct vm_area_struct *vma, struct rb_root *root) #ifdef CONFIG_DEBUG_VM_RB static int browse_rb(struct rb_root *root) { - int i = 0, j; + int i = 0, j, bug = 0; struct rb_node *nd, *pn = NULL; unsigned long prev = 0, pend = 0; @@ -373,39 +373,47 @@ static int browse_rb(struct rb_root *root) struct vm_area_struct *vma; vma = rb_entry(nd, struct vm_area_struct, vm_rb); if (vma->vm_start < prev) - printk("vm_start %lx prev %lx\n", vma->vm_start, prev), i = -1; + printk("vm_start %lx prev %lx\n", vma->vm_start, prev), bug = 1; if (vma->vm_start < pend) - printk("vm_start %lx pend %lx\n", vma->vm_start, pend); + printk("vm_start %lx pend %lx\n", vma->vm_start, pend), bug = 1; if (vma->vm_start > vma->vm_end) - printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start); + printk("vm_end %lx < vm_start %lx\n", vma->vm_end, vma->vm_start), bug = 1; + if (vma->rb_subtree_gap != vma_compute_subtree_gap(vma)) + printk("free gap %lx, correct %lx\n", + vma->rb_subtree_gap, + vma_compute_subtree_gap(vma)), bug = 1; i++; pn = nd; prev = vma->vm_start; pend = vma->vm_end; } j = 0; - for (nd = pn; nd; nd = rb_prev(nd)) { + for (nd = pn; nd; nd = rb_prev(nd)) j++; - } if (i != j) - printk("backwards %d, forwards %d\n", j, i), i = 0; - return i; + printk("backwards %d, forwards %d\n", j, i), bug = 1; + return bug ? -1 : i; } void validate_mm(struct mm_struct *mm) { int bug = 0; int i = 0; + unsigned long highest_address = 0; 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); + highest_address = vma->vm_end; vma = vma->vm_next; i++; } if (i != mm->map_count) printk("map_count %d vm_next %d\n", mm->map_count, i), bug = 1; + if (highest_address != mm->highest_vm_end) + printk("mm->highest_vm_end %lx, found %lx\n", + mm->highest_vm_end, highest_address), bug = 1; i = browse_rb(&mm->mm_rb); if (i != mm->map_count) printk("map_count %d rb %d\n", mm->map_count, i), bug = 1; -- 1.7.7.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org