From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 9678E721 for ; Mon, 19 Oct 2015 19:23:49 +0000 (UTC) Received: from mail-lf0-f43.google.com (mail-lf0-f43.google.com [209.85.215.43]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id E4BF61C1 for ; Mon, 19 Oct 2015 19:23:48 +0000 (UTC) Received: by lfaz124 with SMTP id z124so120500693lfa.1 for ; Mon, 19 Oct 2015 12:23:47 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20151019185220.GA3068@thunk.org> References: <561FD92D.6010309@sr71.net> <20151016210820.GA23471@gmail.com> <20151019182923.GB5907@thunk.org> <20151019185220.GA3068@thunk.org> Date: Mon, 19 Oct 2015 12:23:47 -0700 Message-ID: From: Dan Williams To: "Theodore Ts'o" Content-Type: text/plain; charset=UTF-8 Cc: ksummit-discuss@lists.linuxfoundation.org Subject: Re: [Ksummit-discuss] ZONE_DEVICE and Persistent Memory (was: Re: Draft agenda for the kernel summit) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, Oct 19, 2015 at 11:52 AM, Theodore Ts'o wrote: > On Mon, Oct 19, 2015 at 02:29:23PM -0400, Theodore Ts'o wrote: >> On Fri, Oct 16, 2015 at 05:08:21PM -0400, Jerome Glisse wrote: >> > On Thu, Oct 15, 2015 at 09:49:49AM -0700, Dave Hansen wrote: >> > > On 10/14/2015 05:17 PM, Dan Williams wrote: >> > > > I am wondering if it would be productive / good use of time to do a >> > > > direction check on the mm changes being done in support of large >> > > > persistent memory devices. >> > > >> > > I think there's probably an even wider discussion that we should have here. >> > > >> > > Beyond just ZONE_DEVICE, the sheer number of memory types is increasing >> > > fast, and our current solutions are, at best, inconsistent. We currently >> > > handle memory types as new zones, repurposed zones, pageblocks inside >> > > zones, or faux NUMA nodes. >> > > >> > > Are our current solutions too erratic? >> > > Do we need to solve these problems generally, or are we going to kill >> > > ourselves trying to make everyone happy? >> > > What types do we ignore today, but shouldn't? >> > > What types are coming down the pike? >> > >> > I think what i am working on (HMM and how to leverage GPU memory that is >> > not accessible by the CPU) apply here too. All features i am working on >> > imply that i have to dig through layers of code seeing if i can abuse an >> > existing mechanism to achieve something new. >> > >> > So i definitly think we should discuss where we are and where we want to >> > be. >> >> Dan, would you be willing to kick off the discussion? > > Oops, sorry, it was pointed out to me that Dan isn't going to be at > the Kernel Summit. Jerome, would you be willing to kick off the > discussion and report back to Dan? Well, you were right the first time ;-), I'm booked and registered. Yes, I'd be willing to kick off the discussion.