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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 37D6BC43331 for ; Sat, 7 Sep 2019 17:34:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 000B7218AE for ; Sat, 7 Sep 2019 17:34:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="nX/ZnggV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405231AbfIGReR (ORCPT ); Sat, 7 Sep 2019 13:34:17 -0400 Received: from mail-io1-f68.google.com ([209.85.166.68]:36254 "EHLO mail-io1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391932AbfIGReR (ORCPT ); Sat, 7 Sep 2019 13:34:17 -0400 Received: by mail-io1-f68.google.com with SMTP id b136so20000611iof.3; Sat, 07 Sep 2019 10:34:16 -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=N1wlSEAd/yNqPov8hazkmuwObylmLJ4n7bwZJ/zSVuE=; b=nX/ZnggVrPn3mYrpQxjYzUSqOuhzl/Ki5d8x3fcQRyY95Cjdq1FR5XidwxJPXoE/dV ZHjSR7XLoGr/iym/ChD9eSJEuFtDFm8uelqpCDpSX7XudnAFzhbf8XZ1wToB3ict3D4U keROyrkJ3FgyFny6SfjibZCyAQMgxj5sllN1PcQxPFrUFRWOC39gCuT6KuyWpJubsJse XP1pvczx/jTBbWkozRPfFqR/BTxq+/1RYD0e8OXBS9Wvhh/X46gVFOwitx1Ktt+sviQp v/TPYnp44btB5msp/R2dN2+IYXaZNdSEfeKjTqrv4w0VoCUsnuh+OfNBMKkzCWp0N4eW HPZA== 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=N1wlSEAd/yNqPov8hazkmuwObylmLJ4n7bwZJ/zSVuE=; b=OpEfy92wfPgKFXNCclAi6/2F1kaoPBaNJ+AiJdsdQdW8CrkSiP0HMwbHk1cnThMB7M ogbVGWQbdqGt+3jRLjwcDwGpCZGqUuENn2x/nSgJ2EsY6W1wlEAGp22g4D0FiYDAaVI7 4BaKY/wpijcNlcNt5iT55Q4T34YXP7ya/pFeyrZ+TPj1aanr3Dt+1kmniDEMZm6lqI1b DXR4TBoQHEizCHDyumSoMWk1hJvnk04phIpsu5jP/RjT8l3gAduCpKMbuYNWJxEcaPYY aEoeBPGvMEXMzfndUVeSFGebhBNWdFOIqUeAf/DTobUuh9BnkjeyCerKGGy2npYfcU/Q JhvQ== X-Gm-Message-State: APjAAAV+xRmip/LMXMk69EKBC02j6lX88XFk4ysV0KfqNq5kn27dL7nc 4QWUtT/4E2OPD90PmwKCwYlSKF0z0ujv01577Bg= X-Google-Smtp-Source: APXvYqyL3r6EbggbESVOvEQiUNQ4L6hRKzNiJBvs6HGzqjTYf6K0GuLb4ShQNBqLt7AfI5UmxbdCaqcrjN2rBGALtkA= X-Received: by 2002:a5d:8f86:: with SMTP id l6mr3723909iol.270.1567877655886; Sat, 07 Sep 2019 10:34:15 -0700 (PDT) MIME-Version: 1.0 References: <20190907172225.10910.34302.stgit@localhost.localdomain> In-Reply-To: <20190907172225.10910.34302.stgit@localhost.localdomain> From: Alexander Duyck Date: Sat, 7 Sep 2019 10:34:04 -0700 Message-ID: Subject: Re: [PATCH v9 0/8] mm / virtio: Provide support for unused page reporting To: virtio-dev@lists.oasis-open.org, kvm list , "Michael S. Tsirkin" , Catalin Marinas , David Hildenbrand , Dave Hansen , LKML , Matthew Wilcox , Michal Hocko , linux-mm , Andrew Morton , will@kernel.org, linux-arm-kernel@lists.infradead.org, Oscar Salvador Cc: Yang Zhang , Pankaj Gupta , Konrad Rzeszutek Wilk , Nitesh Narayan Lal , Rik van Riel , lcapitulino@redhat.com, "Wang, Wei W" , Andrea Arcangeli , ying.huang@intel.com, Paolo Bonzini , Dan Williams , Fengguang Wu , Alexander Duyck , "Kirill A. Shutemov" Content-Type: text/plain; charset="UTF-8" Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Sorry about that. Looks like I fat fingered things and copied the command line into the cover page. I corrected the subject here, and pulled the command line out of the message below. - Alex On Sat, Sep 7, 2019 at 10:25 AM Alexander Duyck wrote: > This series provides an asynchronous means of reporting 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 unused page reporting > > The functionality for this is fairly simple. When enabled it will allocate > statistics to track the number of reported pages in a given free area. > When the number of free pages exceeds this value plus a high water value, > currently 32, it will begin performing page reporting which consists of > pulling pages off of free list and placing them into a scatter list. The > scatterlist is then given to the page reporting device and it will perform > the required action to make the pages "reported", in the case of > virtio-balloon this results in the pages being madvised as MADV_DONTNEED > and as such they are forced out of the guest. After this they are placed > back on the free list, and an additional bit is added if they are not > merged indicating that they are a reported buddy page instead of a > standard buddy page. The cycle then repeats with additional non-reported > pages being pulled until the free areas all consist of reported pages. > > I am 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 the limit is on how many pages it wants to allocate to > process the hints. The upper limit for this is based on the size of the > queue used to store the scattergather list. > > My primary testing has just been to verify the memory is being freed after > allocation by running memhog 40g on a 40g guest and watching the total > free memory via /proc/meminfo on the host. With this I have verified most > of the memory is freed after each iteration. As far as performance I have > been mainly focusing on the will-it-scale/page_fault1 test running with > 16 vcpus. I have modified it to use Transparent Huge Pages. With this I > see almost no difference, -0.08%, with the patches applied and the feature > disabled. I see a regression of -0.86% with the feature enabled, but the > madvise disabled in the hypervisor due to a device being assigned. With > the feature fully enabled I see a regression of -3.27% versus the baseline > without these patches applied. In my testing I found that most of the > overhead was due to the page zeroing that comes as a result of the pages > having to be faulted back into the guest. > > One side effect of these patches is that the guest becomes much more > resilient in terms of NUMA locality. With the pages being freed and then > reallocated when used it allows for the pages to be much closer to the > active thread, and as a result there can be situations where this patch > set will out-perform the stock kernel when the guest memory is not local > to the guest vCPUs. To avoid that in my testing I set the affinity of all > the vCPUs and QEMU instance to the same node. > > I have not included the QEMU patches with this set as they haven't really > changed in the last several revisions. If needed they can be located with > the v8 patchset. > > Changes from the RFC: > https://lore.kernel.org/lkml/20190530215223.13974.22445.stgit@localhost.localdomain/ > Moved aeration requested flag out of aerator and into zone->flags. > Moved boundary out of free_area and into local variables for aeration. > Moved aeration cycle out of interrupt and into workqueue. > Left nr_free as total pages instead of splitting it between raw and aerated. > Combined size and physical address values in virtio ring into one 64b value. > > Changes from v1: > https://lore.kernel.org/lkml/20190619222922.1231.27432.stgit@localhost.localdomain/ > Dropped "waste page treatment" in favor of "page hinting" > Renamed files and functions from "aeration" to "page_hinting" > Moved from page->lru list to scatterlist > Replaced wait on refcnt in shutdown with RCU and cancel_delayed_work_sync > Virtio now uses scatterlist directly instead of intermediate array > Moved stats out of free_area, now in separate area and pointed to from zone > Merged patch 5 into patch 4 to improve review-ability > Updated various code comments throughout > > Changes from v2: > https://lore.kernel.org/lkml/20190724165158.6685.87228.stgit@localhost.localdomain/ > Dropped "page hinting" in favor of "page reporting" > Renamed files from "hinting" to "reporting" > Replaced "Hinted" page type with "Reported" page flag > Added support for page poisoning while hinting is active > Add QEMU patch that implements PAGE_POISON feature > > Changes from v3: > https://lore.kernel.org/lkml/20190801222158.22190.96964.stgit@localhost.localdomain/ > Added mutex lock around page reporting startup and shutdown > Fixed reference to "page aeration" in patch 2 > Split page reporting function bit out into separate QEMU patch > Limited capacity of scatterlist to vq size - 1 instead of vq size > Added exception handling for case of virtio descriptor allocation failure > > Changes from v4: > https://lore.kernel.org/lkml/20190807224037.6891.53512.stgit@localhost.localdomain/ > Replaced spin_(un)lock with spin_(un)lock_irq in page_reporting_cycle() > Dropped if/continue for ternary operator in page_reporting_process() > Added checks for isolate and cma types to for_each_reporting_migratetype_order > Added virtio-dev, Michal Hocko, and Oscar Salvador to to:/cc: > Rebased on latest linux-next and QEMU git trees > > Changes from v5: > https://lore.kernel.org/lkml/20190812213158.22097.30576.stgit@localhost.localdomain/ > Replaced spin_(un)lock with spin_(un)lock_irq in page_reporting_startup() > Updated shuffle code to use "shuffle_pick_tail" and updated patch description > Dropped storage of order and migratettype while page is being reported > Used get_pfnblock_migratetype to determine migratetype of page > Renamed put_reported_page to free_reported_page, added order as argument > Dropped check for CMA type as I believe we should be reporting those > Added code to allow moving of reported pages into and out of isolation > Defined page reporting order as minimum of Huge Page size vs MAX_ORDER - 1 > Cleaned up use of static branch usage for page_reporting_notify_enabled > > Changes from v6: > https://lore.kernel.org/lkml/20190821145806.20926.22448.stgit@localhost.localdomain/ > Rebased on linux-next for 20190903 > Added jump label to __page_reporting_request so we release RCU read lock > Removed "- 1" from capacity limit based on virtio ring > Added code to verify capacity is non-zero or return error on startup > > Changes from v7: > https://lore.kernel.org/lkml/20190904150920.13848.32271.stgit@localhost.localdomain/ > Updated poison fixes to clear flag if "nosanity" is enabled in kernel config > Split shuffle per-cpu optimization into separate patch > Moved check for !phdev->capacity into reporting patch where it belongs > Added Reviewed-by tags received for v7 > > Changes from v8: > https://lore.kernel.org/lkml/20190906145213.32552.30160.stgit@localhost.localdomain/ > Added patch that moves HPAGE_SIZE definition for ARM64 to match other archs > Switch back to using pageblock_order instead of HUGETLB_ORDER and MAX_ORDER - 1 > Boundary allocation now dynamic to support HUGETLB_PAGE_SIZE_VARIABLE option > Made use of existing code/functions to reduce size of move_to_boundary function > Dropped unused zone pointer from add_to/del_from_boundary functions > Added additional possible mm and arm64 people as reviewers to Cc > Added Reviewed-by tags received for v8 > Fixed missing parameter in kerneldoc > > --- > > Alexander Duyck (8): > mm: Add per-cpu logic to page shuffling > mm: Adjust shuffle code to allow for future coalescing > mm: Move set/get_pcppage_migratetype to mmzone.h > mm: Use zone and order instead of free area in free_list manipulators > arm64: Move hugetlb related definitions out of pgtable.h to page-defs.h > mm: Introduce Reported pages > virtio-balloon: Pull page poisoning config out of free page hinting > virtio-balloon: Add support for providing unused page reports to host > > > arch/arm64/include/asm/page-def.h | 9 + > arch/arm64/include/asm/pgtable.h | 9 - > drivers/virtio/Kconfig | 1 > drivers/virtio/virtio_balloon.c | 87 ++++++++- > include/linux/mmzone.h | 124 ++++++++---- > include/linux/page-flags.h | 11 + > include/linux/page_reporting.h | 178 +++++++++++++++++ > include/uapi/linux/virtio_balloon.h | 1 > mm/Kconfig | 5 > mm/Makefile | 1 > mm/internal.h | 18 ++ > mm/memory_hotplug.c | 1 > mm/page_alloc.c | 217 +++++++++++++++------ > mm/page_reporting.c | 358 +++++++++++++++++++++++++++++++++++ > mm/shuffle.c | 40 ++-- > mm/shuffle.h | 12 + > 16 files changed, 931 insertions(+), 141 deletions(-) > create mode 100644 include/linux/page_reporting.h > create mode 100644 mm/page_reporting.c > > --