From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by kanga.kvack.org (Postfix) with ESMTP id 58CE16B4039 for ; Mon, 27 Aug 2018 07:26:39 -0400 (EDT) Received: by mail-ed1-f72.google.com with SMTP id b4-v6so2129196ede.4 for ; Mon, 27 Aug 2018 04:26:39 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id m44-v6sor504036edm.20.2018.08.27.04.26.37 for (Google Transport Security); Mon, 27 Aug 2018 04:26:38 -0700 (PDT) From: Michal Hocko Subject: [PATCH 2/3] mm, mmu_notifier: be explicit about range invalition non-blocking mode Date: Mon, 27 Aug 2018 13:26:22 +0200 Message-Id: <20180827112623.8992-3-mhocko@kernel.org> In-Reply-To: <20180827112623.8992-1-mhocko@kernel.org> References: <20180827112623.8992-1-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Tetsuo Handa , linux-mm@kvack.org, LKML , Michal Hocko , Jerome Glisse From: Michal Hocko If invalidate_range_start is called for !blocking mode then all callbacks have to guarantee they will no block/sleep. The same obviously applies to invalidate_range_end because this operation pairs with the former and they are called from the same context. Make sure this is appropriately documented. Cc: Jerome Glisse Signed-off-by: Michal Hocko --- include/linux/mmu_notifier.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 133ba78820ee..698e371aafe3 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -153,7 +153,9 @@ struct mmu_notifier_ops { * * If blockable argument is set to false then the callback cannot * sleep and has to return with -EAGAIN. 0 should be returned - * otherwise. + * otherwise. Please note that if invalidate_range_start approves + * a non-blocking behavior then the same applies to + * invalidate_range_end. * */ int (*invalidate_range_start)(struct mmu_notifier *mn, -- 2.18.0