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=-8.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 967CCC18E5B for ; Wed, 11 Mar 2020 12:30:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5C7FF20873 for ; Wed, 11 Mar 2020 12:30:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Cb2TftEZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729339AbgCKMar (ORCPT ); Wed, 11 Mar 2020 08:30:47 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:34036 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729235AbgCKMar (ORCPT ); Wed, 11 Mar 2020 08:30:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583929843; 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; bh=yfddzOhrs8BW7sEdgX8Oe3MsWES9JOmYHC+bAobOVFY=; b=Cb2TftEZzza7Ss8ztYGuWw0sYG+Sjzru9NvikeKmDV8wUgRqKPvpnDKCIqEzSLariJpKAo 1Bsur4LiwrePXC7bfmMFml4f9BXQtDdndiLbM32mfXbznmhd0SZxgZ7NeuNbSSfPdVqQHF 8nUmjZZBFfhC0yQzhRJNFk4Cai7pbHI= 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-413-6YM6DG_IMAKYaja-zLaXiw-1; Wed, 11 Mar 2020 08:30:40 -0400 X-MC-Unique: 6YM6DG_IMAKYaja-zLaXiw-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 3A2C8107ACC7; Wed, 11 Mar 2020 12:30:37 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.36.118.45]) by smtp.corp.redhat.com (Postfix) with ESMTP id 817935C1D4; Wed, 11 Mar 2020 12:30:27 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-hyperv@vger.kernel.org, David Hildenbrand , Vitaly Kuznetsov , Yumei Huang , Igor Mammedov , Baoquan He , Eduardo Habkost , Milan Zamazal , Andrew Morton , Benjamin Herrenschmidt , Greg Kroah-Hartman , Haiyang Zhang , "K. Y. Srinivasan" , Michael Ellerman , Michal Hocko , Oscar Salvador , Paul Mackerras , "Rafael J. Wysocki" , Stephen Hemminger , Thomas Gleixner , Wei Liu , Wei Yang Subject: [PATCH v1 0/5] mm/memory_hotplug: allow to specify a default online_type Date: Wed, 11 Mar 2020 13:30:21 +0100 Message-Id: <20200311123026.16071-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Distributions nowadays use udev rules ([1] [2]) to specify if and how to online hotplugged memory. The rules seem to get more complex with many special cases. Due to the various special cases, CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE cannot be used. All memory hotplug is handled via udev rules. Everytime we hotplug memory, the udev rule will come to the same conclusion. Especially Hyper-V (but also soon virtio-mem) add a lot of memory in separate memory blocks and wait for memory to get onlined by us= er space before continuing to add more memory blocks (to not add memory fast= er than it is getting onlined). This of course slows down the whole memory hotplug process. To make the job of distributions easier and to avoid udev rules that get more and more complicated, let's extend the mechanism provided by - /sys/devices/system/memory/auto_online_blocks - "memhp_default_state=3D" on the kernel cmdline to be able to specify also "online_movable" as well as "online_kernel" =3D=3D=3D Example /usr/libexec/config-memhotplug =3D=3D=3D #!/bin/bash VIRT=3D`systemd-detect-virt --vm` ARCH=3D`uname -p` sense_virtio_mem() { if [ -d "/sys/bus/virtio/drivers/virtio_mem/" ]; then DEVICES=3D`find /sys/bus/virtio/drivers/virtio_mem/ -maxdepth 1 -type= l | wc -l` if [ $DEVICES !=3D "0" ]; then return 0 fi fi return 1 } if [ ! -e "/sys/devices/system/memory/auto_online_blocks" ]; then echo "Memory hotplug configuration support missing in the kernel" exit 1 fi if grep "memhp_default_state=3D" /proc/cmdline > /dev/null; then echo "Memory hotplug configuration overridden in kernel cmdline (memhp_= default_state=3D)" exit 1 fi if [ $VIRT =3D=3D "microsoft" ]; then echo "Detected Hyper-V on $ARCH" # Hyper-V wants all memory in ZONE_NORMAL ONLINE_TYPE=3D"online_kernel" elif sense_virtio_mem; then echo "Detected virtio-mem on $ARCH" # virtio-mem wants all memory in ZONE_NORMAL ONLINE_TYPE=3D"online_kernel" elif [ $ARCH =3D=3D "s390x" ] || [ $ARCH =3D=3D "s390" ]; then echo "Detected $ARCH" # standby memory should not be onlined automatically ONLINE_TYPE=3D"offline" elif [ $ARCH =3D=3D "ppc64" ] || [ $ARCH =3D=3D "ppc64le" ]; then echo "Detected" $ARCH # PPC64 is handled via a user space daemon AFAIK ONLINE_TYPE=3D"offline" elif [ $VIRT =3D=3D "none" ]; then echo "Detected bare-metal on $ARCH" # Bare metal users expect hotplugged memory to be unpluggable. We assum= e # that ZONE imbalances on such enterpise servers cannot happen and is # properly documented ONLINE_TYPE=3D"online_movable" else # TODO: Hypervisors that want to unplug DIMMs and can guarantee that ZO= NE # imbalances won't happen echo "Detected $VIRT on $ARCH" # Usually, ballooning is used in virtual environments, so memory should= go to # ZONE_NORMAL. However, sometimes "movable_node" is relevant. ONLINE_TYPE=3D"online" fi echo "Selected online_type:" $ONLINE_TYPE # Configure what to do with memory that will be hotplugged in the future echo $ONLINE_TYPE 2>/dev/null > /sys/devices/system/memory/auto_online_bl= ocks if [ $? !=3D "0" ]; then echo "Memory hotplug cannot be configured (e.g., old kernel or missing = permissions)" # A backup udev rule should handle old kernels if necessary exit 1 fi # Process all already pluggedd blocks (e.g., DIMMs, but also Hyper-V or v= irtio-mem) if [ $ONLINE_TYPE !=3D "offline" ]; then for MEMORY in /sys/devices/system/memory/memory*; do STATE=3D`cat $MEMORY/state` if [ $STATE =3D=3D "offline" ]; then echo $ONLINE_TYPE > $MEMORY/state fi done fi =3D=3D=3D Example /usr/lib/systemd/system/config-memhotplug.service =3D=3D= =3D [Unit] Description=3DConfigure memory hotplug behavior DefaultDependencies=3Dno Conflicts=3Dshutdown.target Before=3Dsysinit.target shutdown.target After=3Dsystemd-modules-load.service ConditionPathExists=3D|/sys/devices/system/memory/auto_online_blocks [Service] ExecStart=3D/usr/libexec/config-memhotplug Type=3Doneshot TimeoutSec=3D0 RemainAfterExit=3Dyes [Install] WantedBy=3Dsysinit.target =3D=3D=3D Example modification to the 40-redhat.rules [2] =3D=3D=3D diff --git a/40-redhat.rules b/40-redhat.rules-new index 2c690e5..168fd03 100644 --- a/40-redhat.rules +++ b/40-redhat.rules-new @@ -6,6 +6,9 @@ SUBSYSTEM=3D=3D"cpu", ACTION=3D=3D"add", TEST=3D=3D"onlin= e", ATTR{online}=3D=3D"0", ATTR{online} # Memory hotadd request SUBSYSTEM!=3D"memory", GOTO=3D"memory_hotplug_end" ACTION!=3D"add", GOTO=3D"memory_hotplug_end" +# memory hotplug behavior configured +PROGRAM=3D=3D"grep online /sys/devices/system/memory/auto_online_blocks"= , GOTO=3D"memory_hotplug_end" + PROGRAM=3D"/bin/uname -p", RESULT=3D=3D"s390*", GOTO=3D"memory_hotplug_e= nd" ENV{.state}=3D"online" =3D=3D=3D [1] https://github.com/lnykryn/systemd-rhel/pull/281 [2] https://github.com/lnykryn/systemd-rhel/blob/staging/rules/40-redhat.= rules Cc: Vitaly Kuznetsov Cc: Yumei Huang Cc: Igor Mammedov Cc: Baoquan He Cc: Eduardo Habkost Cc: Milan Zamazal David Hildenbrand (5): drivers/base/memory: rename MMOP_ONLINE_KEEP to MMOP_ONLINE drivers/base/memory: map MMOP_OFFLINE to 0 drivers/base/memory: store mapping between MMOP_* and string in an array mm/memory_hotplug: convert memhp_auto_online to store an online_type mm/memory_hotplug: allow to specify a default online_type arch/powerpc/platforms/powernv/memtrace.c | 2 +- drivers/base/memory.c | 71 ++++++++++++----------- drivers/hv/hv_balloon.c | 2 +- include/linux/memory_hotplug.h | 13 ++++- mm/memory_hotplug.c | 17 +++--- 5 files changed, 58 insertions(+), 47 deletions(-) --=20 2.24.1