From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f181.google.com (mail-wi0-f181.google.com [209.85.212.181]) by kanga.kvack.org (Postfix) with ESMTP id 2621C6B0036 for ; Thu, 19 Dec 2013 20:39:21 -0500 (EST) Received: by mail-wi0-f181.google.com with SMTP id hq4so3034370wib.14 for ; Thu, 19 Dec 2013 17:39:20 -0800 (PST) Date: Thu, 19 Dec 2013 20:00:42 -0500 From: Dave Jones Subject: Re: bad page state in 3.13-rc4 Message-ID: <20131220010042.GA32112@redhat.com> References: <20131219155313.GA25771@redhat.com> <20131219181134.GC25385@kmo-pixel> <20131219182920.GG30640@kvack.org> <20131219192621.GA9228@kvack.org> <20131219195352.GB9228@kvack.org> <20131219202416.GA14519@redhat.com> <20131219233854.GD10905@kvack.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131219233854.GD10905@kvack.org> Sender: owner-linux-mm@kvack.org List-ID: To: Benjamin LaHaise Cc: Linus Torvalds , Kent Overstreet , Linux Kernel , linux-mm , Christoph Lameter , Al Viro On Thu, Dec 19, 2013 at 06:38:54PM -0500, Benjamin LaHaise wrote: > On Thu, Dec 19, 2013 at 03:24:16PM -0500, Dave Jones wrote: > > Yes. Note the original trace in this thread was a VM_BUG_ON(atomic_read(&page->_count) <= 0); > > > > Right after these crashes btw, the box locks up solid. So bad that traces don't > > always make it over usb-serial. Annoying. > > I think I finally have an idea what's going on now. Kent's changes in > e34ecee2ae791df674dfb466ce40692ca6218e43 are broken and result in a memory > leak of the aio kioctx. This eventually leads to the system running out of > memory, which ends up triggering the otherwise hard to hit error paths in > aio_setup_ring(). Linus' suggested changes should fix the badness in the > aio_setup_ring(), but more work has to be done to fix up the percpu > reference counting tie in with the aio code. I'll fix this up in the > morning if nobody beats me to it over night, as I'm just heading out right > now. That would explain why I'm having difficulty repeating it in a hurry if it takes hours of runtime for the leak to reach a point where it becomes a problem. Dave -- 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