From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 6288F6B2C3A for ; Thu, 22 Nov 2018 11:51:17 -0500 (EST) Received: by mail-ed1-f71.google.com with SMTP id o21so1369328edq.4 for ; Thu, 22 Nov 2018 08:51:17 -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 z6-v6sor5056633ejq.44.2018.11.22.08.51.15 for (Google Transport Security); Thu, 22 Nov 2018 08:51:15 -0800 (PST) From: Daniel Vetter Subject: [PATCH 2/3] mm, notifier: Catch sleeping/blocking for !blockable Date: Thu, 22 Nov 2018 17:51:05 +0100 Message-Id: <20181122165106.18238-3-daniel.vetter@ffwll.ch> In-Reply-To: <20181122165106.18238-1-daniel.vetter@ffwll.ch> References: <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 , Andrew Morton , Michal Hocko , David Rientjes , =?UTF-8?q?Christian=20K=C3=B6nig?= , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Daniel Vetter We need to make sure implementations don't cheat and don't have a possible schedule/blocking point deeply burried where review can't catch it. I'm not sure whether this is the best way to make sure all the might_sleep() callsites trigger, and it's a bit ugly in the code flow. But it gets the job done. Cc: Andrew Morton Cc: Michal Hocko Cc: David Rientjes Cc: "Christian König" Cc: Daniel Vetter Cc: "Jérôme Glisse" Cc: linux-mm@kvack.org Signed-off-by: Daniel Vetter --- mm/mmu_notifier.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 59e102589a25..4d282cfb296e 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -185,7 +185,13 @@ int __mmu_notifier_invalidate_range_start(struct mm_struct *mm, id = srcu_read_lock(&srcu); hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { if (mn->ops->invalidate_range_start) { - int _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); + int _ret; + + if (IS_ENABLED(CONFIG_DEBUG_ATOMIC_SLEEP) && !blockable) + preempt_disable(); + _ret = mn->ops->invalidate_range_start(mn, mm, start, end, blockable); + if (IS_ENABLED(CONFIG_DEBUG_ATOMIC_SLEEP) && !blockable) + preempt_enable(); if (_ret) { pr_info("%pS callback failed with %d in %sblockable context.\n", mn->ops->invalidate_range_start, _ret, -- 2.19.1