From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt0-f200.google.com (mail-qt0-f200.google.com [209.85.216.200]) by kanga.kvack.org (Postfix) with ESMTP id BABBD6B40C5 for ; Mon, 27 Aug 2018 09:42:35 -0400 (EDT) Received: by mail-qt0-f200.google.com with SMTP id c14-v6so3860764qtc.7 for ; Mon, 27 Aug 2018 06:42:35 -0700 (PDT) Received: from mx1.redhat.com (mx3-rdu2.redhat.com. [66.187.233.73]) by mx.google.com with ESMTPS id x9-v6si5044296qkl.52.2018.08.27.06.42.34 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 27 Aug 2018 06:42:35 -0700 (PDT) Date: Mon, 27 Aug 2018 09:42:32 -0400 From: Jerome Glisse Subject: Re: [PATCH 2/3] mm, mmu_notifier: be explicit about range invalition non-blocking mode Message-ID: <20180827134231.GA3930@redhat.com> References: <20180827112623.8992-1-mhocko@kernel.org> <20180827112623.8992-3-mhocko@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180827112623.8992-3-mhocko@kernel.org> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Andrew Morton , Tetsuo Handa , linux-mm@kvack.org, LKML , Michal Hocko On Mon, Aug 27, 2018 at 01:26:22PM +0200, Michal Hocko wrote: > 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. > > Signed-off-by: Michal Hocko Reviewed-by: Jerome Glisse > --- > 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 >