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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 A276FC7618B for ; Thu, 25 Jul 2019 16:02:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86C6C2238C for ; Thu, 25 Jul 2019 16:02:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389884AbfGYQC0 (ORCPT ); Thu, 25 Jul 2019 12:02:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:50152 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388760AbfGYQCS (ORCPT ); Thu, 25 Jul 2019 12:02:18 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id AEB8DAFFB; Thu, 25 Jul 2019 16:02:17 +0000 (UTC) From: Oscar Salvador To: akpm@linux-foundation.org Cc: dan.j.williams@intel.com, david@redhat.com, pasha.tatashin@soleen.com, mhocko@suse.com, anshuman.khandual@arm.com, Jonathan.Cameron@huawei.com, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador Subject: [PATCH v3 5/5] mm,memory_hotplug: Allow userspace to enable/disable vmemmap Date: Thu, 25 Jul 2019 18:02:07 +0200 Message-Id: <20190725160207.19579-6-osalvador@suse.de> X-Mailer: git-send-email 2.13.7 In-Reply-To: <20190725160207.19579-1-osalvador@suse.de> References: <20190725160207.19579-1-osalvador@suse.de> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It seems that we have some users out there that want to expose all hotpluggable memory to userspace, so this implements a toggling mechanism for those users who want to disable it. By default, vmemmap pages mechanism is enabled. Signed-off-by: Oscar Salvador --- drivers/base/memory.c | 33 +++++++++++++++++++++++++++++++++ include/linux/memory_hotplug.h | 3 +++ mm/memory_hotplug.c | 7 +++++++ 3 files changed, 43 insertions(+) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index d30d0f6c8ad0..5ec6b80de9dd 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -578,6 +578,35 @@ static DEVICE_ATTR_WO(soft_offline_page); static DEVICE_ATTR_WO(hard_offline_page); #endif +#ifdef CONFIG_SPARSEMEM_VMEMMAP +static ssize_t vmemmap_hotplug_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + if (vmemmap_enabled) + return sprintf(buf, "enabled\n"); + else + return sprintf(buf, "disabled\n"); +} + +static ssize_t vmemmap_hotplug_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + if (sysfs_streq(buf, "enable")) + vmemmap_enabled = true; + else if (sysfs_streq(buf, "disable")) + vmemmap_enabled = false; + else + return -EINVAL; + + return count; +} +static DEVICE_ATTR_RW(vmemmap_hotplug); +#endif + /* * Note that phys_device is optional. It is here to allow for * differentiation between which *physical* devices each @@ -794,6 +823,10 @@ static struct attribute *memory_root_attrs[] = { &dev_attr_hard_offline_page.attr, #endif +#ifdef CONFIG_SPARSEMEM_VMEMMAP + &dev_attr_vmemmap_hotplug.attr, +#endif + &dev_attr_block_size_bytes.attr, &dev_attr_auto_online_blocks.attr, NULL diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index e1e8abf22a80..03d227d13301 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -134,6 +134,9 @@ extern int arch_add_memory(int nid, u64 start, u64 size, struct mhp_restrictions *restrictions); extern u64 max_mem_size; +#ifdef CONFIG_SPARSEMEM_VMEMMAP +extern bool vmemmap_enabled; +#endif extern bool memhp_auto_online; /* If movable_node boot option specified */ extern bool movable_node_enabled; diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 09d41339cd11..5ffe5375b87c 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -68,6 +68,10 @@ void put_online_mems(void) bool movable_node_enabled = false; +#ifdef CONFIG_SPARSEMEM_VMEMMAP +bool vmemmap_enabled __read_mostly = true; +#endif + #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE bool memhp_auto_online; #else @@ -1108,6 +1112,9 @@ static unsigned long mhp_check_flags(unsigned long flags) if (!flags) return 0; + if (!vmemmap_enabled) + return 0; + if (flags != MHP_MEMMAP_ON_MEMORY) { WARN(1, "Wrong flags value (%lx). Ignoring flags.\n", flags); return 0; -- 2.12.3