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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 1296FC76191 for ; Wed, 24 Jul 2019 18:00:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DCC7621926 for ; Wed, 24 Jul 2019 18:00:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563991226; bh=eo+jIOgkZGchxfYdMR0P23b0cu0fHAhxdSZDm+t0N2E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=QCcJ80O24YImLUbvY2cc2dQDx70GQF95xl4vTM1OkJkvHDVN41wpgy/bnnbdGwElk A9TyNsZu3wDARkcjZkVvlaOSv3kvtohEBTJqwuUs2bKe63DFyG+WlFDHwNwF/+0fv1 +IVpcyQXGtLM1e/7djDZ1dLeO/NOfAp82ydbM5aA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728130AbfGXSAY (ORCPT ); Wed, 24 Jul 2019 14:00:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:33504 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726298AbfGXSAY (ORCPT ); Wed, 24 Jul 2019 14:00:24 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 167CFADA2; Wed, 24 Jul 2019 18:00:23 +0000 (UTC) Date: Wed, 24 Jul 2019 20:00:22 +0200 From: Michal Hocko To: Christoph Hellwig Cc: Jason Gunthorpe , Ralph Campbell , linux-mm@kvack.org, linux-kernel@vger.kernel.org, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, =?iso-8859-1?B?Suly9G1l?= Glisse , Ben Skeggs Subject: Re: [PATCH] mm/hmm: replace hmm_update with mmu_notifier_range Message-ID: <20190724180022.GD6410@dhcp22.suse.cz> References: <20190723210506.25127-1-rcampbell@nvidia.com> <20190724070553.GA2523@lst.de> <20190724152858.GB28493@ziepe.ca> <20190724153305.GA10681@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190724153305.GA10681@lst.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 24-07-19 17:33:05, Christoph Hellwig wrote: > On Wed, Jul 24, 2019 at 12:28:58PM -0300, Jason Gunthorpe wrote: > > Humm. Actually having looked this some more, I wonder if this is a > > problem: > > What a mess. > > Question: do we even care for the non-blocking events? The only place > where mmu_notifier_invalidate_range_start_nonblock is called is the oom > killer, which means the process is about to die and the pagetable will > get torn down ASAP. Should we just skip them unconditionally? How do you tell whether they are going to block or not without trying? -- Michal Hocko SUSE Labs