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[209.132.180.67]) by mx.google.com with ESMTP id u21si13768424pgm.431.2019.06.25.12.41.02; Tue, 25 Jun 2019 12:41:18 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Ocl1bNLr; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729599AbfFYRBE (ORCPT + 99 others); Tue, 25 Jun 2019 13:01:04 -0400 Received: from mail-io1-f67.google.com ([209.85.166.67]:43821 "EHLO mail-io1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728506AbfFYRBE (ORCPT ); Tue, 25 Jun 2019 13:01:04 -0400 Received: by mail-io1-f67.google.com with SMTP id k20so10438ios.10; Tue, 25 Jun 2019 10:01:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4nh5j4XcTvP6By9QhoNnt2Wmf1hC1P4k60SdPp76T0k=; b=Ocl1bNLr8OYzeu9TD1azuErTT8IzFHOcI287iJQWs6IMZ/x2MG20iUj2WdhhmYvmAv Zk5lyLTO6h+MThMdU2/+IIXgapLAdfy2/NzsZHUjjaHkdyR8SzJzifePWoWbt2Wk3V+V nAbOwcLUJ9Hzk/CkONjV89hTvByIB7QPw8pEzrfdP7W/CK2CUge/r97cvhG3Gy4B7CI6 YHfgMuJdDTDFbHKdRWU1tXveDuOZHRJ5jeZpZQvhhX3oU5ZlvAibv+TUloulaHhRuw39 FkQ4i8MfMB6AuCUZwqXTORgKRnBx9uEKm2Qe6caTvo6JaiEm28MA9JxSpIIvZ8onjSa3 FiUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4nh5j4XcTvP6By9QhoNnt2Wmf1hC1P4k60SdPp76T0k=; b=N2ueKvvlUI8K5pOgr7n5J8hn6Ae0KrX8jnK0lwtN/yZDa6PSoHwFluPJ7M/BUTjKOS oGLeOWKj6zB9lXkEa6sfX32lVrPCdrFGydELRLH4AgTdzcGoA/yPfmmIjZN0FAy+OdBM RFT95JgNN7DhVCJNT+vuDZmzPie+DGrTmn+ZsupcXvsHmGL0R/tzMzH7qPrHFJC9Msh1 /IWZ84FvC7LKH+AyIir98j+kGHdpT5VKH89SIcviJqfkcL1mT0UB4UyhyLh0IiZY6JNl yChPjCaa9d/PHMxaRv3B2aGOWZFfLJ9kZ+0ehGu2pYKv3g3kE20VE6TCz80dipZjZpur d3Iw== X-Gm-Message-State: APjAAAVnMXOUkBMJID0trQIVoBa6GX29ZW65kJx01r3duj4ckVsAPr3t Hl/Du2xpY/sdHvfcgM1CUbpE9iEYV4qh4lV2kfZmWJ5t X-Received: by 2002:a6b:5106:: with SMTP id f6mr17350556iob.15.1561482063168; Tue, 25 Jun 2019 10:01:03 -0700 (PDT) MIME-Version: 1.0 References: <20190619222922.1231.27432.stgit@localhost.localdomain> <8fea71ba-2464-ead8-3802-2241805283cc@intel.com> In-Reply-To: <8fea71ba-2464-ead8-3802-2241805283cc@intel.com> From: Alexander Duyck Date: Tue, 25 Jun 2019 10:00:51 -0700 Message-ID: Subject: Re: [PATCH v1 0/6] mm / virtio: Provide support for paravirtual waste page treatment To: Dave Hansen Cc: David Hildenbrand , Nitesh Narayan Lal , kvm list , "Michael S. Tsirkin" , LKML , linux-mm , Andrew Morton , Yang Zhang , pagupta@redhat.com, Rik van Riel , Konrad Rzeszutek Wilk , lcapitulino@redhat.com, wei.w.wang@intel.com, Andrea Arcangeli , Paolo Bonzini , dan.j.williams@intel.com, Alexander Duyck Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jun 25, 2019 at 7:10 AM Dave Hansen wrote: > > On 6/25/19 12:42 AM, David Hildenbrand wrote: > > On 20.06.19 00:32, Alexander Duyck wrote: > > I still *detest* the terminology, sorry. Can't you come up with a > > simpler terminology that makes more sense in the context of operating > > systems and pages we want to hint to the hypervisor? (that is the only > > use case you are using it for so far) > > It's a wee bit too cute for my taste as well. I could probably live > with it in the data structures, but having it show up out in places like > Kconfig and filenames goes too far. > > For instance, someone seeing memory_aeration.c will have no concept > what's in the file. Could we call it something like memory_paravirt.c? > Or even mm/paravirt.c. Well I couldn't come up with a better explanation of what this was doing, also I wanted to avoid mentioning hinting specifically because there have already been a few series that have been committed upstream that reference this for slightly different purposes such as the one by Wei Wang that was doing free memory tracking for migration purposes, https://lkml.org/lkml/2018/7/10/211. Basically what we are doing is inflating the memory size we can report by inserting voids into the free memory areas. In my mind that matches up very well with what "aeration" is. It is similar to balloon in functionality, however instead of inflating the balloon we are inflating the free_list for higher order free areas by creating voids where the madvised pages were. > Could you talk for a minute about why the straightforward naming like > "hinted/unhinted" wasn't used? Is there something else we could ever > use this infrastructure for that is not related to paravirtualized free > page hinting? I was hoping there might be something in the future that could use the infrastructure if it needed to go through and sort out used versus unused memory. The way things are designed right now for instance there is only really a define that is limiting the lowest order pages that are processed. So if we wanted to use this for another purpose we could replace the AERATOR_MIN_ORDER define with something that is specific to that use case.