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 827676B30BE for ; Fri, 24 Aug 2018 13:33:39 -0400 (EDT) Received: by mail-qt0-f200.google.com with SMTP id l7-v6so8626873qte.2 for ; Fri, 24 Aug 2018 10:33:39 -0700 (PDT) Received: from mx1.redhat.com (mx3-rdu2.redhat.com. [66.187.233.73]) by mx.google.com with ESMTPS id t79-v6si3029993qkt.282.2018.08.24.10.33.38 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Aug 2018 10:33:38 -0700 (PDT) Date: Fri, 24 Aug 2018 13:33:32 -0400 From: Jerome Glisse Subject: Re: [PATCH] mm, oom: distinguish blockable mode for mmu notifiers Message-ID: <20180824173332.GD4244@redhat.com> References: <20180716115058.5559-1-mhocko@kernel.org> <8cbfb09f-0c5a-8d43-1f5e-f3ff7612e289@I-love.SAKURA.ne.jp> <20180824113629.GI29735@dhcp22.suse.cz> <103b1b33-1a1d-27a1-dcf8-5c8ad60056a6@i-love.sakura.ne.jp> <20180824133207.GR29735@dhcp22.suse.cz> <72844762-7398-c770-1702-f945573f4059@i-love.sakura.ne.jp> <20180824151239.GC4244@redhat.com> <20180824164003.GW29735@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20180824164003.GW29735@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Tetsuo Handa , Andrew Morton , LKML , linux-mm@kvack.org, "David (ChunMing) Zhou" , Paolo Bonzini , Radim =?utf-8?B?S3LEjW3DocWZ?= , Alex Deucher , David Airlie , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Doug Ledford , Jason Gunthorpe , Mike Marciniszyn , Dennis Dalessandro , Sudeep Dutt , Ashutosh Dixit , Dimitri Sivanich , Boris Ostrovsky , Juergen Gross , Andrea Arcangeli , Felix Kuehling , kvm@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-rdma@vger.kernel.org, xen-devel@lists.xenproject.org, Christian =?iso-8859-1?Q?K=F6nig?= , David Rientjes , Leon Romanovsky On Fri, Aug 24, 2018 at 06:40:03PM +0200, Michal Hocko wrote: > On Fri 24-08-18 11:12:40, Jerome Glisse wrote: > [...] > > I am fine with Michal patch, i already said so couple month ago first time > > this discussion did pop up, Michal you can add: > > > > Reviewed-by: Jerome Glisse > > So I guess the below is the patch you were talking about? > > From f7ac75277d526dccd011f343818dc6af627af2af Mon Sep 17 00:00:00 2001 > From: Michal Hocko > Date: Fri, 24 Aug 2018 15:32:24 +0200 > Subject: [PATCH] mm, mmu_notifier: be explicit about range invalition > non-blocking mode > > 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. In my branch i already updated HMM to be like other existing user ie all blocking operation in the start callback. But yes it would be wise to added such comments. > > 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 > > -- > Michal Hocko > SUSE Labs