From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AA14C433F4 for ; Fri, 24 Aug 2018 17:33:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0CEF32151C for ; Fri, 24 Aug 2018 17:33:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0CEF32151C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727626AbeHXVJQ (ORCPT ); Fri, 24 Aug 2018 17:09:16 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:39334 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726277AbeHXVJP (ORCPT ); Fri, 24 Aug 2018 17:09:15 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 088AC87A78; Fri, 24 Aug 2018 17:33:38 +0000 (UTC) Received: from redhat.com (ovpn-125-224.rdu2.redhat.com [10.10.125.224]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0DE402156889; Fri, 24 Aug 2018 17:33:33 +0000 (UTC) Date: Fri, 24 Aug 2018 13:33:32 -0400 From: Jerome Glisse 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 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> User-Agent: Mutt/1.10.0 (2018-05-17) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 24 Aug 2018 17:33:38 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 24 Aug 2018 17:33:38 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jglisse@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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: Jérôme 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