From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3xLnkZ1pBTzDsPt for ; Tue, 1 Aug 2017 04:18:14 +1000 (AEST) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v6VIDuoj038619 for ; Mon, 31 Jul 2017 14:18:11 -0400 Received: from e24smtp04.br.ibm.com (e24smtp04.br.ibm.com [32.104.18.25]) by mx0a-001b2d01.pphosted.com with ESMTP id 2c26xegkp5-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 31 Jul 2017 14:18:10 -0400 Received: from localhost by e24smtp04.br.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 31 Jul 2017 15:18:09 -0300 Received: from d24av01.br.ibm.com (d24av01.br.ibm.com [9.8.31.91]) by d24relay02.br.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v6VII6kD23330862 for ; Mon, 31 Jul 2017 15:18:06 -0300 Received: from d24av01.br.ibm.com (localhost [127.0.0.1]) by d24av01.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v6VII684010823 for ; Mon, 31 Jul 2017 15:18:07 -0300 Received: from localhost.localdomain ([9.80.223.205]) by d24av01.br.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id v6VII4YA010737 for ; Mon, 31 Jul 2017 15:18:05 -0300 From: Daniel Henrique Barboza To: linuxppc-dev@lists.ozlabs.org Subject: [RFC PATCH] powerpc: Disabling MEMORY_HOTPLUG_DEFAULT_ONLINE option for PPC64 arch Date: Mon, 31 Jul 2017 15:17:59 -0300 Message-Id: <20170731181759.13839-1-danielhb@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Commit 943db62c316c ("powerpc/pseries: Revert 'Auto-online hotplugged memory'") reverted the auto-online feature for pseries due to problems with LMB removals not updating the device struct properly. Among other things, this commit made the following change in arch/powerpc/configs/pseries_defconfig: @@ -58,7 +58,6 @@ CONFIG_KEXEC_FILE=y CONFIG_IRQ_ALL_CPUS=y CONFIG_MEMORY_HOTPLUG=y CONFIG_MEMORY_HOTREMOVE=y -CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE=y CONFIG_KSM=y The intent was to disable the option in the defconfig of pseries, since after that the code doesn't have this support anymore. However, this change alone isn't enough to prevent situations such as [1], where distros can enable the option unaware of the consequences of doing it (e.g. breaking LMB hotplug altogether). Instead of relying on all distros knowing that pseries can't handle CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE=y after 943db62c316c, this patch changes mm/Kconfig to make the MEMORY_HOTPLUG_DEFAULT_ONLINE config unavailable for the PPC64 arch. [1] https://bugzilla.redhat.com/show_bug.cgi?id=1476380 Fixes: 943db62c316c ("powerpc/pseries: Revert 'Auto-online hotplugged memory'") Signed-off-by: Daniel Henrique Barboza --- mm/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/Kconfig b/mm/Kconfig index 48b1af4..a342c77 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -169,7 +169,7 @@ config MEMORY_HOTPLUG_SPARSE config MEMORY_HOTPLUG_DEFAULT_ONLINE bool "Online the newly added memory blocks by default" default n - depends on MEMORY_HOTPLUG + depends on MEMORY_HOTPLUG && !PPC64 help This option sets the default policy setting for memory hotplug onlining policy (/sys/devices/system/memory/auto_online_blocks) which -- 2.9.4