Re: [PATCH v2 2/2] mem-hotplug: Introduce MMOP_OFFLINE to replace the hard coding -1.
From: Hu Tao
Date: Fri Jun 06 2014 - 01:19:40 EST
On Fri, Jun 06, 2014 at 11:58:54AM +0800, Tang Chen wrote:
> In store_mem_state(), we have:
> ......
> 334 else if (!strncmp(buf, "offline", min_t(int, count, 7)))
> 335 online_type = -1;
> ......
> 355 case -1:
> 356 ret = device_offline(&mem->dev);
> 357 break;
> ......
>
> Here, "offline" is hard coded as -1.
>
> This patch does the following renaming:
> ONLINE_KEEP -> MMOP_ONLINE_KEEP
> ONLINE_KERNEL -> MMOP_ONLINE_KERNEL
> ONLINE_MOVABLE -> MMOP_ONLINE_MOVABLE
>
> and introduce MMOP_OFFLINE = -1 to avoid hard coding.
>
> Signed-off-by: Tang Chen <tangchen@xxxxxxxxxxxxxx>
> ---
> drivers/base/memory.c | 16 ++++++++--------
> include/linux/memory_hotplug.h | 9 +++++----
> mm/memory_hotplug.c | 9 ++++++---
> 3 files changed, 19 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index fa664b9..0f3fa8c 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -294,7 +294,7 @@ static int memory_subsys_online(struct device *dev)
> * attribute and need to set the online_type.
> */
> if (mem->online_type < 0)
> - mem->online_type = ONLINE_KEEP;
> + mem->online_type = MMOP_ONLINE_KEEP;
>
> ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
>
> @@ -326,22 +326,22 @@ store_mem_state(struct device *dev,
> return ret;
>
> if (sysfs_streq(buf, "online_kernel"))
> - online_type = ONLINE_KERNEL;
> + online_type = MMOP_ONLINE_KERNEL;
> else if (sysfs_streq(buf, "online_movable"))
> - online_type = ONLINE_MOVABLE;
> + online_type = MMOP_ONLINE_MOVABLE;
> else if (sysfs_streq(buf, "online"))
> - online_type = ONLINE_KEEP;
> + online_type = MMOP_ONLINE_KEEP;
> else if (sysfs_streq(buf, "offline"))
> - online_type = -1;
> + online_type = MMOP_OFFLINE;
> else {
> ret = -EINVAL;
> goto err;
> }
>
> switch (online_type) {
> - case ONLINE_KERNEL:
> - case ONLINE_MOVABLE:
> - case ONLINE_KEEP:
> + case MMOP_ONLINE_KERNEL:
> + case MMOP_ONLINE_MOVABLE:
> + case MMOP_ONLINE_KEEP:
There is a `case -1' several lines below should have been converted.
> /*
> * mem->online_type is not protected so there can be a
> * race here. However, when racing online, the first
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 4ca3d95..b4240cf 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -26,11 +26,12 @@ enum {
> MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE = NODE_INFO,
> };
>
> -/* Types for control the zone type of onlined memory */
> +/* Types for control the zone type of onlined and offlined memory */
> enum {
> - ONLINE_KEEP,
> - ONLINE_KERNEL,
> - ONLINE_MOVABLE,
> + MMOP_OFFLINE = -1,
> + MMOP_ONLINE_KEEP,
> + MMOP_ONLINE_KERNEL,
> + MMOP_ONLINE_MOVABLE,
> };
>
> /*
> diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
> index a650db2..6075f04 100644
> --- a/mm/memory_hotplug.c
> +++ b/mm/memory_hotplug.c
> @@ -907,19 +907,22 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
> */
> zone = page_zone(pfn_to_page(pfn));
>
> - if ((zone_idx(zone) > ZONE_NORMAL || online_type == ONLINE_MOVABLE) &&
> + if ((zone_idx(zone) > ZONE_NORMAL ||
> + online_type == MMOP_ONLINE_MOVABLE) &&
> !can_online_high_movable(zone)) {
> unlock_memory_hotplug();
> return -EINVAL;
> }
>
> - if (online_type == ONLINE_KERNEL && zone_idx(zone) == ZONE_MOVABLE) {
> + if (online_type == MMOP_ONLINE_KERNEL &&
> + zone_idx(zone) == ZONE_MOVABLE) {
> if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages)) {
> unlock_memory_hotplug();
> return -EINVAL;
> }
> }
> - if (online_type == ONLINE_MOVABLE && zone_idx(zone) == ZONE_MOVABLE - 1) {
> + if (online_type == MMOP_ONLINE_MOVABLE &&
> + zone_idx(zone) == ZONE_MOVABLE - 1) {
> if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages)) {
> unlock_memory_hotplug();
> return -EINVAL;
> --
> 1.8.3.1
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