From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by kanga.kvack.org (Postfix) with ESMTP id C4A536B2C19 for ; Thu, 22 Nov 2018 11:51:14 -0500 (EST) Received: by mail-ed1-f70.google.com with SMTP id n32-v6so4706286edc.17 for ; Thu, 22 Nov 2018 08:51:14 -0800 (PST) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id x9-v6sor1058377edq.14.2018.11.22.08.51.13 for (Google Transport Security); Thu, 22 Nov 2018 08:51:13 -0800 (PST) From: Daniel Vetter Subject: [PATCH 0/3] RFC: mmu notifier debug checks Date: Thu, 22 Nov 2018 17:51:03 +0100 Message-Id: <20181122165106.18238-1-daniel.vetter@ffwll.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: LKML Cc: Linux MM , Intel Graphics Development , DRI Development , Daniel Vetter Hi all, We're having some good fun with the i915 mmu notifier (it deadlocks), and I think it'd be very useful to have a bunch more runtime debug checks to catch screw-ups. I'm also working on some lockdep improvements in gpu code (better annotations and stuff like that). Together with this series here this seems to catch a lot of bugs pretty much instantly, which previously took hours/days of CI workloads to reproduce. Plus now you get nice backtraces and the kernel keeps working, whereas without this it's real deadlocks with piles of stuck processes (the deadlock needed at least 3 processes, but generally it took more to close the loop, plus everyone piling in on top). If this looks like a good idea I'm happy to polish it for merging. Thanks, Daniel Daniel Vetter (3): mm: Check if mmu notifier callbacks are allowed to fail mm, notifier: Catch sleeping/blocking for !blockable mm, notifier: Add a lockdep map for invalidate_range_start include/linux/mmu_notifier.h | 7 +++++++ mm/mmu_notifier.c | 17 ++++++++++++++++- 2 files changed, 23 insertions(+), 1 deletion(-) -- 2.19.1