From patchwork Fri Sep 11 10:34:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 11770283 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 161E517D4 for ; Fri, 11 Sep 2020 10:35:57 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DE8B220578 for ; Fri, 11 Sep 2020 10:35:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GtwJqSsa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE8B220578 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kGgP4-0002EW-9X; Fri, 11 Sep 2020 10:35:38 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1kGgP2-0002Cd-KO for xen-devel@lists.xenproject.org; Fri, 11 Sep 2020 10:35:36 +0000 X-Inumbo-ID: a51e1bdc-7d42-48ee-a854-404cb01f17fa Received: from us-smtp-1.mimecast.com (unknown [205.139.110.61]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTP id a51e1bdc-7d42-48ee-a854-404cb01f17fa; Fri, 11 Sep 2020 10:35:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1599820529; 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=1KuXxBJDT9q7FMGTTmPve0j4GWux8SlD+IUyrucmwlw=; b=GtwJqSsajUx7DE+lq7cRijZyPE2r5nfRqG5MZJvyBR9cnq48KqceYRagMhvzJCCGKipPVe rYkpSt84nej8T3GwaQSppK1Msn9JW9CRiEdpkHcnU9bCOBd9imFJjHlw4sg0vgaHK8cvah 78Tz+z2EPxTuj44sXZ0+apkGPB14/eQ= 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-586-oFPkKPz2OhqR_nzBBqVMxA-1; Fri, 11 Sep 2020 06:35:25 -0400 X-MC-Unique: oFPkKPz2OhqR_nzBBqVMxA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CA7358064AF; Fri, 11 Sep 2020 10:35:19 +0000 (UTC) Received: from t480s.redhat.com (ovpn-113-186.ams2.redhat.com [10.36.113.186]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7A83881C49; Fri, 11 Sep 2020 10:35:00 +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_Pau_Monn=C3=A9?= , Stefano Stabellini , Stephen Hemminger , Thomas Gleixner , Vasily Gorbik , Vishal Verma , Wei Liu , Wei Yang Subject: [PATCH v4 0/8] selective merging of system ram resources Date: Fri, 11 Sep 2020 12:34:51 +0200 Message-Id: <20200911103459.10306-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" 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. v3 -> v4: - "mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG" -- Fix configs without CONFIG_MEMORY_HOTPLUG with the new mhp_t type -- Did a buch of cross-compiles with different configs, hope there isn't anything I missed. 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 like 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 resource name has to be specified to "merge_system_ram_resources(). - Smaller comment/documentation/patch description changes/fixes David Hildenbrand (8): kernel/resource: make release_mem_region_adjustable() never fail kernel/resource: move and rename IORESOURCE_MEM_DRIVER_MANAGED mm/memory_hotplug: guard more declarations by CONFIG_MEMORY_HOTPLUG 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 | 35 +++--- kernel/kexec_file.c | 2 +- kernel/resource.c | 109 ++++++++++++++---- mm/memory_hotplug.c | 47 +++----- mm/sparse.c | 2 + 15 files changed, 151 insertions(+), 77 deletions(-)