Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753648AbaDCVob (ORCPT ); Thu, 3 Apr 2014 17:44:31 -0400 Received: from g2t2353.austin.hp.com ([15.217.128.52]:3503 "EHLO g2t2353.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752711AbaDCVoC (ORCPT ); Thu, 3 Apr 2014 17:44:02 -0400 Message-ID: <1396561440.4661.33.camel@buesod1.americas.hpqcorp.net> Subject: [RFC] mm,tracing: improve current situation From: Davidlohr Bueso To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Dave Jones , Sasha Levin , Andrew Morton Date: Thu, 03 Apr 2014 14:44:00 -0700 Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi All, During LSFMM Dave Jones discussed the current situation around testing/trinity in the mm. One of the conclusions was that basically we lack tools to gather the necessary information to make debugging a less painful process, making it pretty much a black box for a lot of cases. One of the suggested ways to do so was to improve our tracing. Currently we have events for kmem, vmscan and oom (which really just traces the tunable updates) -- In addition Dave Hansen also also been trying to add tracing for TLB range flushing, hopefully that can make it in some time soon. However, this lacks the more general data that governs all of the core VM, such as vmas and of course the mm_struct. To this end, I've started adding events to trace the vma lifecycle, including: creating, removing, splitting, merging, copying and adjusting. Currently it only prints out the start and end virtual addresses, such as: bash-3661 [000] .... 222.964847: split_vma: [8a8000-9a6000] => new: [9a6000-9b6000] Now, on a more general scenario, I basically would like to know, 1) is this actually useful... I'm hoping that, if in fact something like this gets merged, it won't just sit there. 2) What other general data would be useful for debugging purposes? I'm happy to collect feedback and send out something we can all benefit from. Thanks, Davidlohr -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/