From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:41975 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750753AbeBSFCL (ORCPT ); Mon, 19 Feb 2018 00:02:11 -0500 Date: Mon, 19 Feb 2018 16:02:09 +1100 From: Dave Chinner Subject: Re: freezing system for several second on high I/O [kernel 4.15] Message-ID: <20180219050209.GY7000@dastard> References: <1518255240.31843.6.camel@gmail.com> <1518255352.31843.8.camel@gmail.com> <20180211225657.GA6778@dastard> <1518643669.6070.21.camel@gmail.com> <20180214215245.GI7000@dastard> <1518666178.6070.25.camel@gmail.com> <20180215054436.GN7000@dastard> <20180215214858.GQ7000@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Mikhail Gavrilov Cc: "linux-xfs@vger.kernel.org" , "linux-mm@kvack.org" On Sun, Feb 18, 2018 at 07:02:37PM +0500, Mikhail Gavrilov wrote: > On 16 February 2018 at 02:48, Dave Chinner wrote: > > On Fri, Feb 16, 2018 at 12:02:28AM +0500, Mikhail Gavrilov wrote: > >> On 15 February 2018 at 10:44, Dave Chinner wrote: > >> > I've already explained that we can't annotate these memory > >> > allocations to turn off the false positives because that will also > >> > turning off all detection of real deadlock conditions. Lockdep has > >> > many, many limitations, and this happens to be one of them. > >> > > >> > FWIW, is there any specific reason you running lockdep on your > >> > desktop system? > >> > >> Because I wanna make open source better (help fixing all freezing) > > > > lockdep isn't a user tool - most developers don't even understand > > what it tries to tell them. Worse, it is likely contributing to your > > problems as it has a significant runtime CPU and memory overhead.... > > I don't know how else collect debug info about freezes which occurring > accidentally. Is there a better idea? Lockdep tells us about locking problems, not arbitrary operational latencies. Go look at the bcc collection of tools for tracking down where latencies occur in the system. -Dave. -- Dave Chinner david@fromorbit.com