From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kirill A. Shutemov" Subject: Re: [PATCH] mm: pass VM_BUG_ON() reason to dump_page() Date: Fri, 11 Apr 2014 23:36:57 +0300 Message-ID: <20140411203657.GA672@node.dhcp.inet.fi> References: <20140411202125.01D1D100@viggo.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140411202125.01D1D100@viggo.jf.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: Dave Hansen Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-Id: linux-mm.kvack.org On Fri, Apr 11, 2014 at 01:21:25PM -0700, Dave Hansen wrote: > > From: Dave Hansen > > I recently added a patch to let folks pass a "reason" string > dump_page() which gets dumped out along with the page's data. > This essentially saves the bug-reader a trip in to the source > to figure out why we BUG_ON()'d. > > The new VM_BUG_ON_PAGE() passes in NULL for "reason". It seems > like we might as well pass the BUG_ON() condition if we have it. > This will bloat kernels a bit with ~160 new strings, but this > is all under a debugging option anyway. > > page:ffffea0008560280 count:1 mapcount:0 mapping:(null) index:0x0 > page flags: 0xbfffc0000000001(locked) > page dumped because: VM_BUG_ON_PAGE(PageLocked(page)) > ------------[ cut here ]------------ > kernel BUG at /home/davehans/linux.git/mm/filemap.c:464! > invalid opcode: 0000 [#1] SMP > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #251 > Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 > ... > > > Signed-off-by: Dave Hansen I see space-before-tabs in few places, otherwise: Acked-by: Kirill A. Shutemov -- Kirill A. Shutemov