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 62015C2BC11 for ; Fri, 11 Sep 2020 10:35:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B144B22206 for ; Fri, 11 Sep 2020 10:35:31 +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="GtwJqSsa" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B144B22206 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 3E8996B0068; Fri, 11 Sep 2020 06:35:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3BDF06B006C; Fri, 11 Sep 2020 06:35:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2B0358E0001; Fri, 11 Sep 2020 06:35:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0151.hostedemail.com [216.40.44.151]) by kanga.kvack.org (Postfix) with ESMTP id 134BF6B0068 for ; Fri, 11 Sep 2020 06:35:31 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id CFB281EE6 for ; Fri, 11 Sep 2020 10:35:30 +0000 (UTC) X-FDA: 77250424020.09.side55_060f681270ee Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin09.hostedemail.com (Postfix) with ESMTP id A4B4D180AD807 for ; Fri, 11 Sep 2020 10:35:30 +0000 (UTC) X-HE-Tag: side55_060f681270ee X-Filterd-Recvd-Size: 7858 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by imf32.hostedemail.com (Postfix) with ESMTP for ; 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=20Pau=20Monn=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 Content-Type: text/plain; charset=UTF-8 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Rspamd-Queue-Id: A4B4D180AD807 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam04 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. 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 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 (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(-) --=20 2.26.2