From: Oscar Salvador <osalvador@suse.de>
To: akpm@linux-foundation.org
Cc: mhocko@suse.com, dan.j.williams@intel.com,
pasha.tatashin@soleen.com, Jonathan.Cameron@huawei.com,
david@redhat.com, anshuman.khandual@arm.com, vbabka@suse.cz,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Oscar Salvador <osalvador@suse.de>
Subject: [PATCH v2 5/5] mm,memory_hotplug: Allow userspace to enable/disable vmemmap
Date: Tue, 25 Jun 2019 09:52:27 +0200 [thread overview]
Message-ID: <20190625075227.15193-6-osalvador@suse.de> (raw)
In-Reply-To: <20190625075227.15193-1-osalvador@suse.de>
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 <osalvador@suse.de>
---
drivers/base/memory.c | 33 +++++++++++++++++++++++++++++++++
include/linux/memory_hotplug.h | 3 +++
mm/memory_hotplug.c | 6 +++++-
3 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index e0ac9a3b66f8..6fca2c96cc08 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -573,6 +573,35 @@ 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
@@ -799,6 +828,10 @@ 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 e28e226c9a20..94b4adc1a0ba 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -131,6 +131,9 @@ 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 b5106cb75795..32ee6fb7d3bf 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -70,6 +70,10 @@ 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
@@ -1168,7 +1172,7 @@ int __ref add_memory_resource(int nid, struct resource *res, unsigned long flags
goto error;
new_node = ret;
- if (mhp_check_correct_flags(flags))
+ if (vmemmap_enabled && mhp_check_correct_flags(flags))
restrictions.flags = flags;
/* call arch's memory hotadd */
--
2.12.3
next prev parent reply other threads:[~2019-06-25 7:53 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-25 7:52 [PATCH v2 0/5] Allocate memmap from hotadded memory Oscar Salvador
2019-06-25 7:52 ` [PATCH v2 1/5] drivers/base/memory: Remove unneeded check in remove_memory_block_devices Oscar Salvador
2019-06-25 8:01 ` David Hildenbrand
2019-06-25 8:03 ` David Hildenbrand
2019-06-25 8:09 ` Oscar Salvador
2019-06-25 8:27 ` David Hildenbrand
2019-06-25 7:52 ` [PATCH v2 2/5] mm,memory_hotplug: Introduce MHP_VMEMMAP_FLAGS Oscar Salvador
2019-06-25 8:31 ` David Hildenbrand
2019-07-24 20:11 ` Dan Williams
2019-07-24 21:36 ` osalvador
2019-07-25 9:27 ` Oscar Salvador
2019-07-25 9:30 ` David Hildenbrand
2019-07-25 9:40 ` Oscar Salvador
2019-07-25 10:04 ` David Hildenbrand
2019-07-25 10:13 ` Oscar Salvador
2019-07-25 10:15 ` David Hildenbrand
2019-06-25 7:52 ` [PATCH v2 3/5] mm,memory_hotplug: Introduce Vmemmap page helpers Oscar Salvador
2019-06-25 7:52 ` [PATCH v2 4/5] mm,memory_hotplug: allocate memmap from the added memory range for sparse-vmemmap Oscar Salvador
2019-06-25 8:49 ` David Hildenbrand
2019-06-26 8:13 ` Oscar Salvador
2019-06-26 8:15 ` David Hildenbrand
2019-06-26 8:17 ` Anshuman Khandual
2019-06-26 8:28 ` Oscar Salvador
2019-07-24 21:49 ` Dan Williams
2019-06-25 7:52 ` Oscar Salvador [this message]
2019-06-25 8:25 ` [PATCH v2 0/5] Allocate memmap from hotadded memory David Hildenbrand
2019-06-25 8:33 ` David Hildenbrand
2019-06-26 8:03 ` Oscar Salvador
2019-06-26 8:11 ` David Hildenbrand
2019-06-26 8:15 ` Oscar Salvador
2019-06-26 8:27 ` Oscar Salvador
2019-06-26 8:37 ` David Hildenbrand
2019-06-26 8:28 ` David Hildenbrand
2019-07-02 6:42 ` Rashmica Gupta
2019-07-02 7:48 ` Oscar Salvador
[not found] ` <CAC6rBskRyh5Tj9L-6T4dTgA18H0Y8GsMdC-X5_0Jh1SVfLLYtg@mail.gmail.com>
2019-07-10 1:14 ` Rashmica Gupta
2019-07-31 12:08 ` Michal Hocko
2019-07-31 23:06 ` Rashmica Gupta
2019-08-01 7:17 ` Michal Hocko
2019-08-01 7:18 ` David Hildenbrand
2019-08-01 7:24 ` Michal Hocko
2019-08-01 7:26 ` David Hildenbrand
2019-08-01 7:31 ` David Hildenbrand
2019-08-01 7:39 ` Michal Hocko
2019-08-01 7:48 ` Michal Hocko
2019-08-01 9:18 ` David Hildenbrand
2019-08-01 7:34 ` Michal Hocko
2019-08-01 7:50 ` David Hildenbrand
2019-08-01 8:04 ` Michal Hocko
2019-07-16 12:28 ` David Hildenbrand
2019-07-29 5:42 ` Rashmica Gupta
2019-07-29 8:06 ` David Hildenbrand
2019-07-30 7:08 ` Rashmica Gupta
2019-07-31 2:21 ` Rashmica Gupta
2019-07-31 9:39 ` David Hildenbrand
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