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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 E3D4AC43461 for ; Thu, 10 Sep 2020 09:14:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4B9AF207DE for ; Thu, 10 Sep 2020 09:14:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LOEx2RId" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4B9AF207DE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id B19AD6B005D; Thu, 10 Sep 2020 05:14:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AC8AD6B0062; Thu, 10 Sep 2020 05:14:12 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9DE656B0068; Thu, 10 Sep 2020 05:14:12 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0254.hostedemail.com [216.40.44.254]) by kanga.kvack.org (Postfix) with ESMTP id 8512F6B005D for ; Thu, 10 Sep 2020 05:14:12 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 50C68180AD815 for ; Thu, 10 Sep 2020 09:14:12 +0000 (UTC) X-FDA: 77246590344.23.stone87_141800d270e4 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin23.hostedemail.com (Postfix) with ESMTP id 11FF237609 for ; Thu, 10 Sep 2020 09:14:12 +0000 (UTC) X-HE-Tag: stone87_141800d270e4 X-Filterd-Recvd-Size: 7481 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Thu, 10 Sep 2020 09:14:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599729251; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=q+xRLYk6ElaQMFati+s8ZI/gmN1ETJt7O5tUW1WhghI=; b=LOEx2RIdvDfYdRRFKvUUvqqeSMPqBKYRBBVxB6JuJx2X9PNuBJbQE3NNrPbO34UQxkigtx 0qR2B43fqpt4i9ouRZtS7t4JvPSKKnXOWqeseacDgWtfDsdAeVWDRDHGKVRj7h9myuzj7i Jv61QunEzyEArtdf/JUXJ7N5cxWtT8A= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-308-3iuqD9l8MNi4UpNNbX7W8g-1; Thu, 10 Sep 2020 05:14:07 -0400 X-MC-Unique: 3iuqD9l8MNi4UpNNbX7W8g-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4996418B9F00; Thu, 10 Sep 2020 09:14:01 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-88.ams2.redhat.com [10.36.113.88]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2A880282CA; Thu, 10 Sep 2020 09:13:41 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: virtualization@lists.linux-foundation.org, linux-mm@kvack.org, linux-hyperv@vger.kernel.org, xen-devel@lists.xenproject.org, linux-acpi@vger.kernel.org, linux-nvdimm@lists.01.org, linux-s390@vger.kernel.org, Andrew Morton , David Hildenbrand , Andrew Morton , Anton Blanchard , Ard Biesheuvel , Baoquan He , Benjamin Herrenschmidt , Boris Ostrovsky , Christian Borntraeger , Dan Williams , Dave Jiang , Eric Biederman , Greg Kroah-Hartman , Haiyang Zhang , Heiko Carstens , Jason Gunthorpe , Jason Wang , Juergen Gross , Julien Grall , Kees Cook , "K. Y. Srinivasan" , Len Brown , Leonardo Bras , Libor Pechacek , Michael Ellerman , "Michael S. Tsirkin" , Michal Hocko , Nathan Lynch , "Oliver O'Halloran" , Pankaj Gupta , Paul Mackerras , Pingfan Liu , "Rafael J. Wysocki" , =?UTF-8?q?Roger=20Pau=20Monn=C3=A9?= , Stefano Stabellini , Stephen Hemminger , Thomas Gleixner , Vasily Gorbik , Vishal Verma , Wei Liu , Wei Yang Subject: [PATCH v3 0/7] mm/memory_hotplug: selective merging of system ram resources Date: Thu, 10 Sep 2020 11:13:33 +0200 Message-Id: <20200910091340.8654-1-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Rspamd-Queue-Id: 11FF237609 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Some add_memory*() users add memory in small, contiguous memory blocks. Examples include virtio-mem, hyper-v balloon, and the XEN balloon. This can quickly result in a lot of memory resources, whereby the actual resource boundaries are not of interest (e.g., it might be relevant for DIMMs, exposed via /proc/iomem to user space). We really want to merge added resources in this scenario where possible. Resources are effectively stored in a list-based tree. Having a lot of resources not only wastes memory, it also makes traversing that tree more expensive, and makes /proc/iomem explode in size (e.g., requiring kexec-tools to manually merge resources when creating a kdump header. The current kexec-tools resource count limit does not allow for more than ~100GB of memory with a memory block size of 128MB on x86-64). Let's allow to selectively merge system ram resources by specifying a new flag for add_memory*(). Patch #5 contains a /proc/iomem example. Only tested with virtio-mem. v2 -> v3: - "mm/memory_hotplug: prepare passing flags to add_memory() and friends" -- Use proper __bitwise type for flags -- Use "MHP_NONE" for empty flags - Rebased to latest -next, added rb's v1 -> v2: - I had another look at v1 after vacation and didn't like it - it felt li= ke a hack. So I want forward and added a proper flag to add_memory*(), and introduce a clean (non-racy) way to mark System RAM resources mergeable= . - "kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED" -- Clean that flag up, felt wrong in the PnP section - "mm/memory_hotplug: prepare passing flags to add_memory() and friends" -- Previously sent in other context - decided to keep Wei's ack - "mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System RAM resources" -- Cleaner approach to get the job done by using proper flags and only merging the single, specified resource - "virtio-mem: try to merge system ram resources" "xen/balloon: try to merge system ram resources" "hv_balloon: try to merge system ram resources" -- Use the new flag MEMHP_MERGE_RESOURCE, much cleaner RFC -> v1: - Switch from rather generic "merge_child_mem_resources()" where a resour= ce name has to be specified to "merge_system_ram_resources(). - Smaller comment/documentation/patch description changes/fixes David Hildenbrand (7): kernel/resource: make release_mem_region_adjustable() never fail kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED mm/memory_hotplug: prepare passing flags to add_memory() and friends mm/memory_hotplug: MEMHP_MERGE_RESOURCE to specify merging of System RAM resources virtio-mem: try to merge system ram resources xen/balloon: try to merge system ram resources hv_balloon: try to merge system ram resources arch/powerpc/platforms/powernv/memtrace.c | 2 +- .../platforms/pseries/hotplug-memory.c | 2 +- drivers/acpi/acpi_memhotplug.c | 3 +- drivers/base/memory.c | 3 +- drivers/dax/kmem.c | 2 +- drivers/hv/hv_balloon.c | 2 +- drivers/s390/char/sclp_cmd.c | 2 +- drivers/virtio/virtio_mem.c | 3 +- drivers/xen/balloon.c | 2 +- include/linux/ioport.h | 12 +- include/linux/memory_hotplug.h | 23 +++- kernel/kexec_file.c | 2 +- kernel/resource.c | 109 ++++++++++++++---- mm/memory_hotplug.c | 47 +++----- 14 files changed, 146 insertions(+), 68 deletions(-) --=20 2.26.2