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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 8A0F3C04AB6 for ; Fri, 31 May 2019 11:16:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 561B32681F for ; Fri, 31 May 2019 11:16:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727210AbfEaLQk (ORCPT ); Fri, 31 May 2019 07:16:40 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33388 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726002AbfEaLQk (ORCPT ); Fri, 31 May 2019 07:16:40 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 00BD730C1214; Fri, 31 May 2019 11:16:34 +0000 (UTC) Received: from [10.40.205.96] (unknown [10.40.205.96]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4E0901001DED; Fri, 31 May 2019 11:16:21 +0000 (UTC) Subject: Re: [RFC PATCH 00/11] mm / virtio: Provide support for paravirtual waste page treatment To: Alexander Duyck , kvm@vger.kernel.org, david@redhat.com, mst@redhat.com, dave.hansen@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Cc: yang.zhang.wz@gmail.com, pagupta@redhat.com, riel@surriel.com, konrad.wilk@oracle.com, lcapitulino@redhat.com, wei.w.wang@intel.com, aarcange@redhat.com, pbonzini@redhat.com, dan.j.williams@intel.com, alexander.h.duyck@linux.intel.com References: <20190530215223.13974.22445.stgit@localhost.localdomain> From: Nitesh Narayan Lal Openpgp: preference=signencrypt Autocrypt: addr=nitesh@redhat.com; prefer-encrypt=mutual; keydata= mQINBFl4pQoBEADT/nXR2JOfsCjDgYmE2qonSGjkM1g8S6p9UWD+bf7YEAYYYzZsLtbilFTe z4nL4AV6VJmC7dBIlTi3Mj2eymD/2dkKP6UXlliWkq67feVg1KG+4UIp89lFW7v5Y8Muw3Fm uQbFvxyhN8n3tmhRe+ScWsndSBDxYOZgkbCSIfNPdZrHcnOLfA7xMJZeRCjqUpwhIjxQdFA7 n0s0KZ2cHIsemtBM8b2WXSQG9CjqAJHVkDhrBWKThDRF7k80oiJdEQlTEiVhaEDURXq+2XmG jpCnvRQDb28EJSsQlNEAzwzHMeplddfB0vCg9fRk/kOBMDBtGsTvNT9OYUZD+7jaf0gvBvBB lbKmmMMX7uJB+ejY7bnw6ePNrVPErWyfHzR5WYrIFUtgoR3LigKnw5apzc7UIV9G8uiIcZEn C+QJCK43jgnkPcSmwVPztcrkbC84g1K5v2Dxh9amXKLBA1/i+CAY8JWMTepsFohIFMXNLj+B RJoOcR4HGYXZ6CAJa3Glu3mCmYqHTOKwezJTAvmsCLd3W7WxOGF8BbBjVaPjcZfavOvkin0u DaFvhAmrzN6lL0msY17JCZo046z8oAqkyvEflFbC0S1R/POzehKrzQ1RFRD3/YzzlhmIowkM BpTqNBeHEzQAlIhQuyu1ugmQtfsYYq6FPmWMRfFPes/4JUU/PQARAQABtCVOaXRlc2ggTmFy YXlhbiBMYWwgPG5pbGFsQHJlZGhhdC5jb20+iQI9BBMBCAAnBQJZeKUKAhsjBQkJZgGABQsJ CAcCBhUICQoLAgQWAgMBAh4BAheAAAoJEKOGQNwGMqM56lEP/A2KMs/pu0URcVk/kqVwcBhU SnvB8DP3lDWDnmVrAkFEOnPX7GTbactQ41wF/xwjwmEmTzLrMRZpkqz2y9mV0hWHjqoXbOCS 6RwK3ri5e2ThIPoGxFLt6TrMHgCRwm8YuOSJ97o+uohCTN8pmQ86KMUrDNwMqRkeTRW9wWIQ EdDqW44VwelnyPwcmWHBNNb1Kd8j3xKlHtnS45vc6WuoKxYRBTQOwI/5uFpDZtZ1a5kq9Ak/ MOPDDZpd84rqd+IvgMw5z4a5QlkvOTpScD21G3gjmtTEtyfahltyDK/5i8IaQC3YiXJCrqxE r7/4JMZeOYiKpE9iZMtS90t4wBgbVTqAGH1nE/ifZVAUcCtycD0f3egX9CHe45Ad4fsF3edQ ESa5tZAogiA4Hc/yQpnnf43a3aQ67XPOJXxS0Qptzu4vfF9h7kTKYWSrVesOU3QKYbjEAf95 NewF9FhAlYqYrwIwnuAZ8TdXVDYt7Z3z506//sf6zoRwYIDA8RDqFGRuPMXUsoUnf/KKPrtR ceLcSUP/JCNiYbf1/QtW8S6Ca/4qJFXQHp0knqJPGmwuFHsarSdpvZQ9qpxD3FnuPyo64S2N Dfq8TAeifNp2pAmPY2PAHQ3nOmKgMG8Gn5QiORvMUGzSz8Lo31LW58NdBKbh6bci5+t/HE0H pnyVf5xhNC/FuQINBFl4pQoBEACr+MgxWHUP76oNNYjRiNDhaIVtnPRqxiZ9v4H5FPxJy9UD Bqr54rifr1E+K+yYNPt/Po43vVL2cAyfyI/LVLlhiY4yH6T1n+Di/hSkkviCaf13gczuvgz4 KVYLwojU8+naJUsiCJw01MjO3pg9GQ+47HgsnRjCdNmmHiUQqksMIfd8k3reO9SUNlEmDDNB XuSzkHjE5y/R/6p8uXaVpiKPfHoULjNRWaFc3d2JGmxJpBdpYnajoz61m7XJlgwl/B5Ql/6B dHGaX3VHxOZsfRfugwYF9CkrPbyO5PK7yJ5vaiWre7aQ9bmCtXAomvF1q3/qRwZp77k6i9R3 tWfXjZDOQokw0u6d6DYJ0Vkfcwheg2i/Mf/epQl7Pf846G3PgSnyVK6cRwerBl5a68w7xqVU 4KgAh0DePjtDcbcXsKRT9D63cfyfrNE+ea4i0SVik6+N4nAj1HbzWHTk2KIxTsJXypibOKFX 2VykltxutR1sUfZBYMkfU4PogE7NjVEU7KtuCOSAkYzIWrZNEQrxYkxHLJsWruhSYNRsqVBy KvY6JAsq/i5yhVd5JKKU8wIOgSwC9P6mXYRgwPyfg15GZpnw+Fpey4bCDkT5fMOaCcS+vSU1 UaFmC4Ogzpe2BW2DOaPU5Ik99zUFNn6cRmOOXArrryjFlLT5oSOe4IposgWzdwARAQABiQIl BBgBCAAPBQJZeKUKAhsMBQkJZgGAAAoJEKOGQNwGMqM5ELoP/jj9d9gF1Al4+9bngUlYohYu 0sxyZo9IZ7Yb7cHuJzOMqfgoP4tydP4QCuyd9Q2OHHL5AL4VFNb8SvqAxxYSPuDJTI3JZwI7 d8JTPKwpulMSUaJE8ZH9n8A/+sdC3CAD4QafVBcCcbFe1jifHmQRdDrvHV9Es14QVAOTZhnJ vweENyHEIxkpLsyUUDuVypIo6y/Cws+EBCWt27BJi9GH/EOTB0wb+2ghCs/i3h8a+bi+bS7L FCCm/AxIqxRurh2UySn0P/2+2eZvneJ1/uTgfxnjeSlwQJ1BWzMAdAHQO1/lnbyZgEZEtUZJ x9d9ASekTtJjBMKJXAw7GbB2dAA/QmbA+Q+Xuamzm/1imigz6L6sOt2n/X/SSc33w8RJUyor SvAIoG/zU2Y76pKTgbpQqMDmkmNYFMLcAukpvC4ki3Sf086TdMgkjqtnpTkEElMSFJC8npXv 3QnGGOIfFug/qs8z03DLPBz9VYS26jiiN7QIJVpeeEdN/LKnaz5LO+h5kNAyj44qdF2T2AiF HxnZnxO5JNP5uISQH3FjxxGxJkdJ8jKzZV7aT37sC+Rp0o3KNc+GXTR+GSVq87Xfuhx0LRST NK9ZhT0+qkiN7npFLtNtbzwqaqceq3XhafmCiw8xrtzCnlB/C4SiBr/93Ip4kihXJ0EuHSLn VujM7c/b4pps Organization: Red Hat Inc, Message-ID: <34c0ea04-720f-6915-6a99-b05e5eb87968@redhat.com> Date: Fri, 31 May 2019 07:16:19 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190530215223.13974.22445.stgit@localhost.localdomain> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Fri, 31 May 2019 11:16:39 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/30/19 5:53 PM, Alexander Duyck wrote: > This series provides an asynchronous means of hinting to a hypervisor > that a guest page is no longer in use and can have the data associated > with it dropped. To do this I have implemented functionality that allows > for what I am referring to as "waste page treatment". > > I have based many of the terms and functionality off of waste water > treatment, the idea for the similarity occured to me after I had reached > the point of referring to the hints as "bubbles", as the hints used the > same approach as the balloon functionality but would disappear if they > were touched, as a result I started to think of the virtio device as an > aerator. The general idea with all of this is that the guest should be > treating the unused pages so that when they end up heading "downstream" > to either another guest, or back at the host they will not need to be > written to swap. > > So for a bit of background for the treatment process, it is based on a > sequencing batch reactor (SBR)[1]. The treatment process itself has five > stages. The first stage is the fill, with this we take the raw pages and > add them to the reactor. The second stage is react, in this stage we hand > the pages off to the Virtio Balloon driver to have hints attached to them > and for those hints to be sent to the hypervisor. The third stage is > settle, in this stage we are waiting for the hypervisor to process the > pages, and we should receive an interrupt when it is completed. The fourth > stage is to decant, or drain the reactor of pages. Finally we have the > idle stage which we will go into if the reference count for the reactor > gets down to 0 after a drain, or if a fill operation fails to obtain any > pages and the reference count has hit 0. Otherwise we return to the first > state and start the cycle over again. > > This patch set is still far more intrusive then I would really like for > what it has to do. Currently I am splitting the nr_free_pages into two > values and having to add a pointer and an index to track where we area in > the treatment process for a given free_area. I'm also not sure I have > covered all possible corner cases where pages can get into the free_area > or move from one migratetype to another. > > Also I am still leaving a number of things hard-coded such as limiting the > lowest order processed to PAGEBLOCK_ORDER, and have left it up to the > guest to determine what size of reactor it wants to allocate to process > the hints. > > Another consideration I am still debating is if I really want to process > the aerator_cycle() function in interrupt context or if I should have it > running in a thread somewhere else. Can you please share some performance numbers? I will be sharing a less mm-intrusive bitmap-based approach hopefully by next week. Let's compare the two approaches then, in the meanwhile I will start reviewing your patch-set. > > [1]: https://en.wikipedia.org/wiki/Sequencing_batch_reactor > > --- > > Alexander Duyck (11): > mm: Move MAX_ORDER definition closer to pageblock_order > mm: Adjust shuffle code to allow for future coalescing > mm: Add support for Treated Buddy pages > mm: Split nr_free into nr_free_raw and nr_free_treated > mm: Propogate Treated bit when splitting > mm: Add membrane to free area to use as divider between treated and raw pages > mm: Add support for acquiring first free "raw" or "untreated" page in zone > mm: Add support for creating memory aeration > mm: Count isolated pages as "treated" > virtio-balloon: Add support for aerating memory via bubble hinting > mm: Add free page notification hook > > > arch/x86/include/asm/page.h | 11 + > drivers/virtio/Kconfig | 1 > drivers/virtio/virtio_balloon.c | 89 ++++++++++ > include/linux/gfp.h | 10 + > include/linux/memory_aeration.h | 54 ++++++ > include/linux/mmzone.h | 100 +++++++++-- > include/linux/page-flags.h | 32 +++ > include/linux/pageblock-flags.h | 8 + > include/uapi/linux/virtio_balloon.h | 1 > mm/Kconfig | 5 + > mm/Makefile | 1 > mm/aeration.c | 324 +++++++++++++++++++++++++++++++++++ > mm/compaction.c | 4 > mm/page_alloc.c | 220 ++++++++++++++++++++---- > mm/shuffle.c | 24 --- > mm/shuffle.h | 35 ++++ > mm/vmstat.c | 5 - > 17 files changed, 838 insertions(+), 86 deletions(-) > create mode 100644 include/linux/memory_aeration.h > create mode 100644 mm/aeration.c > > -- -- Regards Nitesh