From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f174.google.com (mail-pd0-f174.google.com [209.85.192.174]) by kanga.kvack.org (Postfix) with ESMTP id 7D8C76B0036 for ; Thu, 4 Sep 2014 16:31:02 -0400 (EDT) Received: by mail-pd0-f174.google.com with SMTP id v10so992836pde.33 for ; Thu, 04 Sep 2014 13:31:00 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id pd4si5556640pdb.173.2014.09.04.13.30.59 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Sep 2014 13:31:00 -0700 (PDT) Date: Thu, 4 Sep 2014 13:30:58 -0700 From: Andrew Morton Subject: Re: [PATCH] mm: mmap: use pr_emerg when printing BUG related information Message-Id: <20140904133058.37ca7aa2e46a607eed94df3b@linux-foundation.org> In-Reply-To: <1409855782-15089-1-git-send-email-sasha.levin@oracle.com> References: <1409855782-15089-1-git-send-email-sasha.levin@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Sasha Levin Cc: oleg@redhat.com, riel@redhat.com, kirill.shutemov@linux.intel.com, luto@amacapital.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, 4 Sep 2014 14:36:22 -0400 Sasha Levin wrote: > Make sure we actually see the output of validate_mm() and browse_rb() > before triggering a BUG(). pr_info isn't shown by default so the reason > for the BUG() isn't obvious. > yup, I'll scoot that into 3.17. That code's actually pretty cruddy. How does this look? From: Andrew Morton Subject: mm/mmap.c: clean up CONFIG_DEBUG_VM_RB checks - be consistent in printing the test which failed - one message was actually wrong (aa) - don't print second bogus warning if browse_rb() failed Cc: Sasha Levin Signed-off-by: Andrew Morton --- mm/mmap.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff -puN mm/mmap.c~mm-mmapc-clean-up-config_debug_vm_rb-checks mm/mmap.c --- a/mm/mmap.c~mm-mmapc-clean-up-config_debug_vm_rb-checks +++ a/mm/mmap.c @@ -369,16 +369,18 @@ static int browse_rb(struct rb_root *roo struct vm_area_struct *vma; vma = rb_entry(nd, struct vm_area_struct, vm_rb); if (vma->vm_start < prev) { - pr_emerg("vm_start %lx prev %lx\n", vma->vm_start, prev); + pr_emerg("vm_start %lx < prev %lx\n", + vma->vm_start, prev); bug = 1; } if (vma->vm_start < pend) { - pr_emerg("vm_start %lx pend %lx\n", vma->vm_start, pend); + pr_emerg("vm_start %lx < pend %lx\n", + vma->vm_start, pend); bug = 1; } if (vma->vm_start > vma->vm_end) { - pr_emerg("vm_end %lx < vm_start %lx\n", - vma->vm_end, vma->vm_start); + pr_emerg("vm_start %lx > vm_end %lx\n", + vma->vm_start, vma->vm_end); bug = 1; } if (vma->rb_subtree_gap != vma_compute_subtree_gap(vma)) { @@ -420,8 +422,10 @@ static void validate_mm(struct mm_struct int i = 0; unsigned long highest_address = 0; struct vm_area_struct *vma = mm->mmap; + while (vma) { struct anon_vma_chain *avc; + vma_lock_anon_vma(vma); list_for_each_entry(avc, &vma->anon_vma_chain, same_vma) anon_vma_interval_tree_verify(avc); @@ -436,12 +440,13 @@ static void validate_mm(struct mm_struct } if (highest_address != mm->highest_vm_end) { pr_emerg("mm->highest_vm_end %lx, found %lx\n", - mm->highest_vm_end, highest_address); + mm->highest_vm_end, highest_address); bug = 1; } i = browse_rb(&mm->mm_rb); if (i != mm->map_count) { - pr_emerg("map_count %d rb %d\n", mm->map_count, i); + if (i != -1) + pr_emerg("map_count %d rb %d\n", mm->map_count, i); bug = 1; } BUG_ON(bug); _ -- 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