From patchwork Mon Oct 11 08:20:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12549341 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B6201C433F5 for ; Mon, 11 Oct 2021 08:21:17 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6F8E561038 for ; Mon, 11 Oct 2021 08:21:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 6F8E561038 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 0939F6B0071; Mon, 11 Oct 2021 04:21:14 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0432F80008; Mon, 11 Oct 2021 04:21:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E75C480007; Mon, 11 Oct 2021 04:21:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0109.hostedemail.com [216.40.44.109]) by kanga.kvack.org (Postfix) with ESMTP id D779D6B0071 for ; Mon, 11 Oct 2021 04:21:13 -0400 (EDT) Received: from smtpin36.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 7FAD21801D517 for ; Mon, 11 Oct 2021 08:21:13 +0000 (UTC) X-FDA: 78683461626.36.4BAD997 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf02.hostedemail.com (Postfix) with ESMTP id 2AA3570044EB for ; Mon, 11 Oct 2021 08:21:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633940472; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AaKkIEW3HUO2tgQVS8IhxeXIR+5mDtqE3xTnoz6JfNs=; b=cf9tOkM2/BobLFGFcDxIIV6MlUm8WDHqoo31H1ma7SJQbXtiHIeOSRyZDdUSpBLfWXACYY 8SRlJ+sC100u7hkNxHWya/rU59yjFLPlAyGlRSgoYSyV5IGhnExQ/2we2uTgFq+b6P6tlh 8dLqdoICKx7W5DRRY9BcJtRkEpzHsD8= 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-568-RlQM-El_PwiQGJjTk0cxiw-1; Mon, 11 Oct 2021 04:21:09 -0400 X-MC-Unique: RlQM-El_PwiQGJjTk0cxiw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 87868802B40; Mon, 11 Oct 2021 08:21:07 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.192.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4C49D5F707; Mon, 11 Oct 2021 08:21:04 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Andrew Morton , Jonathan Corbet , Michal Hocko , Oscar Salvador , Mike Rapoport , linux-doc@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 1/3] memory-hotplug.rst: fix two instances of "movablecore" that should be "movable_node" Date: Mon, 11 Oct 2021 10:20:56 +0200 Message-Id: <20211011082058.6076-2-david@redhat.com> In-Reply-To: <20211011082058.6076-1-david@redhat.com> References: <20211011082058.6076-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Rspamd-Queue-Id: 2AA3570044EB X-Stat-Signature: 6446hf9ke8c7zozpwhzdw8wgobgctbrm Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=cf9tOkM2; spf=none (imf02.hostedemail.com: domain of david@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Rspamd-Server: rspam06 X-HE-Tag: 1633940472-103239 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: We really want to refer to the "movable_node" kernel command line parameter here. Fixes: ac3332c44767 ("memory-hotplug.rst: complete admin-guide overhaul") Signed-off-by: David Hildenbrand Acked-by: Mike Rapoport --- Documentation/admin-guide/mm/memory-hotplug.rst | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/Documentation/admin-guide/mm/memory-hotplug.rst b/Documentation/admin-guide/mm/memory-hotplug.rst index 03dfbc925252..27d748cb6ee0 100644 --- a/Documentation/admin-guide/mm/memory-hotplug.rst +++ b/Documentation/admin-guide/mm/memory-hotplug.rst @@ -166,7 +166,7 @@ Or alternatively:: % echo 1 > /sys/devices/system/memory/memoryXXX/online The kernel will select the target zone automatically, usually defaulting to -``ZONE_NORMAL`` unless ``movablecore=1`` has been specified on the kernel +``ZONE_NORMAL`` unless ``movable_node`` has been specified on the kernel command line or if the memory block would intersect the ZONE_MOVABLE already. One can explicitly request to associate an offline memory block with @@ -393,7 +393,7 @@ command line parameters are relevant: ======================== ======================================================= ``memhp_default_state`` configure auto-onlining by essentially setting ``/sys/devices/system/memory/auto_online_blocks``. -``movablecore`` configure automatic zone selection of the kernel. When +``movable_node`` configure automatic zone selection in the kernel. When set, the kernel will default to ZONE_MOVABLE, unless other zones can be kept contiguous. ======================== ======================================================= From patchwork Mon Oct 11 08:20:57 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12549343 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D0B3C433EF for ; Mon, 11 Oct 2021 08:21:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CB1C7600CD for ; Mon, 11 Oct 2021 08:21:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org CB1C7600CD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 612C780007; Mon, 11 Oct 2021 04:21:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5C2376B0074; Mon, 11 Oct 2021 04:21:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 489B180007; Mon, 11 Oct 2021 04:21:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0107.hostedemail.com [216.40.44.107]) by kanga.kvack.org (Postfix) with ESMTP id 359E76B0073 for ; Mon, 11 Oct 2021 04:21:18 -0400 (EDT) Received: from smtpin33.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id EA0F629227 for ; Mon, 11 Oct 2021 08:21:17 +0000 (UTC) X-FDA: 78683461794.33.4F981AB Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf20.hostedemail.com (Postfix) with ESMTP id 99D64D00490D for ; Mon, 11 Oct 2021 08:21:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1633940477; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iUT00SFFMSyhOoEnBK2kV8REPmBQWV8bxInejpzsCM8=; b=MwrtSTaS966jaRQcuG7BmIt4bO6igPO+3+A0V+WBghRKWlwoEv6OG9QTrytLsr0iWUHhvs kl1mr4qQ9jnnEpgcCZRrAmoagrNOdkHj3K8syh87iMt7glgNqqxj4XNvDyi14TFFOK05+d VDPWQihgH14/p6LNFwXzu1AAKsPtJTg= 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-3-I-rhEkf_MhatSmPAKr0lJQ-1; Mon, 11 Oct 2021 04:21:14 -0400 X-MC-Unique: I-rhEkf_MhatSmPAKr0lJQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 83E3C801A93; Mon, 11 Oct 2021 08:21:12 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.192.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id E6B095C232; Mon, 11 Oct 2021 08:21:07 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Andrew Morton , Jonathan Corbet , Michal Hocko , Oscar Salvador , Mike Rapoport , linux-doc@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 2/3] memory-hotplug.rst: fix wrong /sys/module/memory_hotplug/parameters/ path Date: Mon, 11 Oct 2021 10:20:57 +0200 Message-Id: <20211011082058.6076-3-david@redhat.com> In-Reply-To: <20211011082058.6076-1-david@redhat.com> References: <20211011082058.6076-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=MwrtSTaS; spf=none (imf20.hostedemail.com: domain of david@redhat.com has no SPF policy when checking 170.10.129.124) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 99D64D00490D X-Stat-Signature: tamxatt63torrc6hdbne5u4xhqanpm3x X-HE-Tag: 1633940477-162692 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: We accidentially added a superfluous "s". Fixes: ac3332c44767 ("memory-hotplug.rst: complete admin-guide overhaul") Signed-off-by: David Hildenbrand Acked-by: Mike Rapoport --- Documentation/admin-guide/mm/memory-hotplug.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/admin-guide/mm/memory-hotplug.rst b/Documentation/admin-guide/mm/memory-hotplug.rst index 27d748cb6ee0..ee00b70dedde 100644 --- a/Documentation/admin-guide/mm/memory-hotplug.rst +++ b/Documentation/admin-guide/mm/memory-hotplug.rst @@ -410,7 +410,7 @@ them with ``memory_hotplug.`` such as:: and they can be observed (and some even modified at runtime) via:: - /sys/modules/memory_hotplug/parameters/ + /sys/module/memory_hotplug/parameters/ The following module parameters are currently defined: From patchwork Mon Oct 11 08:20:58 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 12549345 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C76EC433EF for ; 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Mon, 11 Oct 2021 08:21:15 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.192.99]) by smtp.corp.redhat.com (Postfix) with ESMTP id EA6585FC22; Mon, 11 Oct 2021 08:21:12 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: David Hildenbrand , Andrew Morton , Jonathan Corbet , Michal Hocko , Oscar Salvador , Mike Rapoport , linux-doc@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v2 3/3] memory-hotplug.rst: document the "auto-movable" online policy Date: Mon, 11 Oct 2021 10:20:58 +0200 Message-Id: <20211011082058.6076-4-david@redhat.com> In-Reply-To: <20211011082058.6076-1-david@redhat.com> References: <20211011082058.6076-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Rspamd-Queue-Id: A7FE5D03F2E4 X-Stat-Signature: c3mxhno61dhp4bxgin6r3n7tsxj6agy7 Authentication-Results: imf21.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="idtb/uru"; spf=none (imf21.hostedemail.com: domain of david@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Rspamd-Server: rspam06 X-HE-Tag: 1633940482-579967 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: In commit e83a437faa62 ("mm/memory_hotplug: introduce "auto-movable" online policy") we introduced a new memory online policy to automatically select a zone for memory blocks to be onlined. We added a way to set the active online policy and tunables for the auto-movable online policy. In follow-up commits we tweaked the "auto-movable" policy to also consider memory device details when selecting zones for memory blocks to be onlined. Let's document the new toggles and how the two online policies we have work. Signed-off-by: David Hildenbrand Acked-by: Mike Rapoport --- .../admin-guide/mm/memory-hotplug.rst | 141 +++++++++++++++--- 1 file changed, 121 insertions(+), 20 deletions(-) diff --git a/Documentation/admin-guide/mm/memory-hotplug.rst b/Documentation/admin-guide/mm/memory-hotplug.rst index ee00b70dedde..0f56ecd8ac05 100644 --- a/Documentation/admin-guide/mm/memory-hotplug.rst +++ b/Documentation/admin-guide/mm/memory-hotplug.rst @@ -165,9 +165,8 @@ Or alternatively:: % echo 1 > /sys/devices/system/memory/memoryXXX/online -The kernel will select the target zone automatically, usually defaulting to -``ZONE_NORMAL`` unless ``movable_node`` has been specified on the kernel -command line or if the memory block would intersect the ZONE_MOVABLE already. +The kernel will select the target zone automatically, depending on the +configured ``online_policy``. One can explicitly request to associate an offline memory block with ZONE_MOVABLE by:: @@ -198,6 +197,9 @@ Auto-onlining can be enabled by writing ``online``, ``online_kernel`` or % echo online > /sys/devices/system/memory/auto_online_blocks +Similarly to manual onlining, with ``online`` the kernel will select the +target zone automatically, depending on the configured ``online_policy``. + Modifying the auto-online behavior will only affect all subsequently added memory blocks only. @@ -393,11 +395,16 @@ command line parameters are relevant: ======================== ======================================================= ``memhp_default_state`` configure auto-onlining by essentially setting ``/sys/devices/system/memory/auto_online_blocks``. -``movable_node`` configure automatic zone selection in the kernel. When - set, the kernel will default to ZONE_MOVABLE, unless - other zones can be kept contiguous. +``movable_node`` configure automatic zone selection in the kernel when + using the ``contig-zones`` online policy. When + set, the kernel will default to ZONE_MOVABLE when + onlining a memory block, unless other zones can be kept + contiguous. ======================== ======================================================= +See Documentation/admin-guide/kernel-parameters.txt for a more generic +description of these command line parameters. + Module Parameters ------------------ @@ -414,20 +421,114 @@ and they can be observed (and some even modified at runtime) via:: The following module parameters are currently defined: -======================== ======================================================= -``memmap_on_memory`` read-write: Allocate memory for the memmap from the - added memory block itself. Even if enabled, actual - support depends on various other system properties and - should only be regarded as a hint whether the behavior - would be desired. - - While allocating the memmap from the memory block - itself makes memory hotplug less likely to fail and - keeps the memmap on the same NUMA node in any case, it - can fragment physical memory in a way that huge pages - in bigger granularity cannot be formed on hotplugged - memory. -======================== ======================================================= +================================ =============================================== +``memmap_on_memory`` read-write: Allocate memory for the memmap from + the added memory block itself. Even if enabled, + actual support depends on various other system + properties and should only be regarded as a + hint whether the behavior would be desired. + + While allocating the memmap from the memory + block itself makes memory hotplug less likely + to fail and keeps the memmap on the same NUMA + node in any case, it can fragment physical + memory in a way that huge pages in bigger + granularity cannot be formed on hotplugged + memory. +``online_policy`` read-write: Set the basic policy used for + automatic zone selection when onlining memory + blocks without specifying a target zone. + ``contig-zones`` has been the kernel default + before this parameter was added. After an + online policy was configured and memory was + online, the policy should not be changed + anymore. + + When set to ``contig-zones``, the kernel will + try keeping zones contiguous. If a memory block + intersects multiple zones or no zone, the + behavior depends on the ``movable_node`` kernel + command line parameter: default to ZONE_MOVABLE + if set, default to the applicable kernel zone + (usually ZONE_NORMAL) if not set. + + When set to ``auto-movable``, the kernel will + try onlining memory blocks to ZONE_MOVABLE if + possible according to the configuration and + memory device details. With this policy, one + can avoid zone imbalances when eventually + hotplugging a lot of memory later and still + wanting to be able to hotunplug as much as + possible reliably, very desirable in + virtualized environments. This policy ignores + the ``movable_node`` kernel command line + parameter and isn't really applicable in + environments that require it (e.g., bare metal + with hotunpluggable nodes) where hotplugged + memory might be exposed via the + firmware-provided memory map early during boot + to the system instead of getting detected, + added and onlined later during boot (such as + done by virtio-mem or by some hypervisors + implementing emulated DIMMs). As one example, a + hotplugged DIMM will be onlined either + completely to ZONE_MOVABLE or completely to + ZONE_NORMAL, not a mixture. + As another example, as many memory blocks + belonging to a virtio-mem device will be + onlined to ZONE_MOVABLE as possible, + special-casing units of memory blocks that can + only get hotunplugged together. *This policy + does not protect from setups that are + problematic with ZONE_MOVABLE and does not + change the zone of memory blocks dynamically + after they were onlined.* +``auto_movable_ratio`` read-write: Set the maximum MOVABLE:KERNEL + memory ratio in % for the ``auto-movable`` + online policy. Whether the ratio applies only + for the system across all NUMA nodes or also + per NUMA nodes depends on the + ``auto_movable_numa_aware`` configuration. + + All accounting is based on present memory pages + in the zones combined with accounting per + memory device. Memory dedicated to the CMA + allocator is accounted as MOVABLE, although + residing on one of the kernel zones. The + possible ratio depends on the actual workload. + The kernel default is "301" %, for example, + allowing for hotplugging 24 GiB to a 8 GiB VM + and automatically onlining all hotplugged + memory to ZONE_MOVABLE in many setups. The + additional 1% deals with some pages being not + present, for example, because of some firmware + allocations. + + Note that ZONE_NORMAL memory provided by one + memory device does not allow for more + ZONE_MOVABLE memory for a different memory + device. As one example, onlining memory of a + hotplugged DIMM to ZONE_NORMAL will not allow + for another hotplugged DIMM to get onlined to + ZONE_MOVABLE automatically. In contrast, memory + hotplugged by a virtio-mem device that got + onlined to ZONE_NORMAL will allow for more + ZONE_MOVABLE memory within *the same* + virtio-mem device. +``auto_movable_numa_aware`` read-write: Configure whether the + ``auto_movable_ratio`` in the ``auto-movable`` + online policy also applies per NUMA + node in addition to the whole system across all + NUMA nodes. The kernel default is "Y". + + Disabling NUMA awareness can be helpful when + dealing with NUMA nodes that should be + completely hotunpluggable, onlining the memory + completely to ZONE_MOVABLE automatically if + possible. + + Parameter availability depends on CONFIG_NUMA. +================================ =============================================== ZONE_MOVABLE ============