lkml.org 
[lkml]   [2012]   [Aug]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[RFC v8 PATCH 04/20] memory-hotplug: offline and remove memory when removing the memory device
    Date
    From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

    We should offline and remove memory when removing the memory device.
    The memory device can be removed by 2 ways:
    1. send eject request by SCI
    2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject

    In the 1st case, acpi_memory_disable_device() will be called. In the 2nd
    case, acpi_memory_device_remove() will be called. acpi_memory_device_remove()
    will also be called when we unbind the memory device from the driver
    acpi_memhotplug. If the type is ACPI_BUS_REMOVAL_EJECT, it means
    that the user wants to eject the memory device, and we should offline
    and remove memory in acpi_memory_device_remove().

    The function remove_memory() is not implemeted now. It only check whether
    all memory has been offllined now.

    CC: David Rientjes <rientjes@google.com>
    CC: Jiang Liu <liuj97@gmail.com>
    CC: Len Brown <len.brown@intel.com>
    CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
    CC: Paul Mackerras <paulus@samba.org>
    CC: Christoph Lameter <cl@linux.com>
    Cc: Minchan Kim <minchan.kim@gmail.com>
    CC: Andrew Morton <akpm@linux-foundation.org>
    CC: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
    Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
    Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
    ---
    drivers/acpi/acpi_memhotplug.c | 45 +++++++++++++++++++++++++++++++++------
    drivers/base/memory.c | 39 ++++++++++++++++++++++++++++++++++
    include/linux/memory.h | 5 ++++
    include/linux/memory_hotplug.h | 5 ++++
    mm/memory_hotplug.c | 22 +++++++++++++++++++
    5 files changed, 109 insertions(+), 7 deletions(-)

    diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
    index 7873832..9d47458 100644
    --- a/drivers/acpi/acpi_memhotplug.c
    +++ b/drivers/acpi/acpi_memhotplug.c
    @@ -29,6 +29,7 @@
    #include <linux/module.h>
    #include <linux/init.h>
    #include <linux/types.h>
    +#include <linux/memory.h>
    #include <linux/memory_hotplug.h>
    #include <linux/slab.h>
    #include <acpi/acpi_drivers.h>
    @@ -310,25 +311,44 @@ static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
    return 0;
    }

    -static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
    +static int
    +acpi_memory_device_remove_memory(struct acpi_memory_device *mem_device)
    {
    int result;
    struct acpi_memory_info *info, *n;
    + int node = mem_device->nid;

    -
    - /*
    - * Ask the VM to offline this memory range.
    - * Note: Assume that this function returns zero on success
    - */
    list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
    if (info->enabled) {
    result = offline_memory(info->start_addr, info->length);
    if (result)
    return result;
    +
    + result = remove_memory(node, info->start_addr,
    + info->length);
    + if (result)
    + return result;
    }
    +
    + list_del(&info->list);
    kfree(info);
    }

    + return 0;
    +}
    +
    +static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
    +{
    + int result;
    +
    + /*
    + * Ask the VM to offline this memory range.
    + * Note: Assume that this function returns zero on success
    + */
    + result = acpi_memory_device_remove_memory(mem_device);
    + if (result)
    + return result;
    +
    /* Power-off and eject the device */
    result = acpi_memory_powerdown_device(mem_device);
    if (result) {
    @@ -477,12 +497,23 @@ static int acpi_memory_device_add(struct acpi_device *device)
    static int acpi_memory_device_remove(struct acpi_device *device, int type)
    {
    struct acpi_memory_device *mem_device = NULL;
    -
    + int result;

    if (!device || !acpi_driver_data(device))
    return -EINVAL;

    mem_device = acpi_driver_data(device);
    +
    + if (type == ACPI_BUS_REMOVAL_EJECT) {
    + /*
    + * offline and remove memory only when the memory device is
    + * ejected.
    + */
    + result = acpi_memory_device_remove_memory(mem_device);
    + if (result)
    + return result;
    + }
    +
    kfree(mem_device);

    return 0;
    diff --git a/drivers/base/memory.c b/drivers/base/memory.c
    index 86c8821..038be73 100644
    --- a/drivers/base/memory.c
    +++ b/drivers/base/memory.c
    @@ -70,6 +70,45 @@ void unregister_memory_isolate_notifier(struct notifier_block *nb)
    }
    EXPORT_SYMBOL(unregister_memory_isolate_notifier);

    +bool is_memblk_offline(unsigned long start, unsigned long size)
    +{
    + struct memory_block *mem = NULL;
    + struct mem_section *section;
    + unsigned long start_pfn, end_pfn;
    + unsigned long pfn, section_nr;
    +
    + start_pfn = PFN_DOWN(start);
    + end_pfn = PFN_UP(start + size);
    +
    + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
    + section_nr = pfn_to_section_nr(pfn);
    + if (!present_section_nr(section_nr))
    + continue;
    +
    + section = __nr_to_section(section_nr);
    + /* same memblock? */
    + if (mem)
    + if ((section_nr >= mem->start_section_nr) &&
    + (section_nr <= mem->end_section_nr))
    + continue;
    +
    + mem = find_memory_block_hinted(section, mem);
    + if (!mem)
    + continue;
    + if (mem->state == MEM_OFFLINE)
    + continue;
    +
    + kobject_put(&mem->dev.kobj);
    + return false;
    + }
    +
    + if (mem)
    + kobject_put(&mem->dev.kobj);
    +
    + return true;
    +}
    +EXPORT_SYMBOL(is_memblk_offline);
    +
    /*
    * register_memory - Setup a sysfs device for a memory block
    */
    diff --git a/include/linux/memory.h b/include/linux/memory.h
    index 1ac7f6e..7c66126 100644
    --- a/include/linux/memory.h
    +++ b/include/linux/memory.h
    @@ -106,6 +106,10 @@ static inline int memory_isolate_notify(unsigned long val, void *v)
    {
    return 0;
    }
    +static inline bool is_memblk_offline(unsigned long start, unsigned long size)
    +{
    + return false;
    +}
    #else
    extern int register_memory_notifier(struct notifier_block *nb);
    extern void unregister_memory_notifier(struct notifier_block *nb);
    @@ -120,6 +124,7 @@ extern int memory_isolate_notify(unsigned long val, void *v);
    extern struct memory_block *find_memory_block_hinted(struct mem_section *,
    struct memory_block *);
    extern struct memory_block *find_memory_block(struct mem_section *);
    +extern bool is_memblk_offline(unsigned long start, unsigned long size);
    #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
    enum mem_add_context { BOOT, HOTPLUG };
    #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
    diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
    index 0b040bb..fd84ea9 100644
    --- a/include/linux/memory_hotplug.h
    +++ b/include/linux/memory_hotplug.h
    @@ -222,6 +222,7 @@ static inline void unlock_memory_hotplug(void) {}
    #ifdef CONFIG_MEMORY_HOTREMOVE

    extern int is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
    +extern int remove_memory(int nid, u64 start, u64 size);

    #else
    static inline int is_mem_section_removable(unsigned long pfn,
    @@ -229,6 +230,10 @@ static inline int is_mem_section_removable(unsigned long pfn,
    {
    return 0;
    }
    +static inline int remove_memory(int nid, u64 start, u64 size)
    +{
    + return -EBUSY;
    +}
    #endif /* CONFIG_MEMORY_HOTREMOVE */

    extern int mem_online_node(int nid);
    diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
    index 3113cd4..80cded7 100644
    --- a/mm/memory_hotplug.c
    +++ b/mm/memory_hotplug.c
    @@ -1038,6 +1038,28 @@ int offline_memory(u64 start, u64 size)

    return 0;
    }
    +
    +int remove_memory(int nid, u64 start, u64 size)
    +{
    + int ret = -EBUSY;
    + lock_memory_hotplug();
    + /*
    + * The memory might become online by other task, even if you offine it.
    + * So we check whether the cpu has been onlined or not.
    + */
    + if (!is_memblk_offline(start, size)) {
    + pr_warn("memory removing [mem %#010llx-%#010llx] failed, "
    + "because the memmory range is online\n",
    + start, start + size);
    + ret = -EAGAIN;
    + }
    +
    + unlock_memory_hotplug();
    + return ret;
    +
    +}
    +EXPORT_SYMBOL_GPL(remove_memory);
    +
    #else
    int offline_pages(u64 start, u64 size)
    {
    --
    1.7.1


    \
     
     \ /
      Last update: 2012-08-28 12:42    [W:7.158 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site