Re: [PATCH v1 2/5] drivers/base/memory: map MMOP_OFFLINE to 0

2020-03-16 Thread Michal Hocko
On Wed 11-03-20 13:30:23, David Hildenbrand wrote:
> I have no idea why we have to start at -1.

Because this is how the offline state offline was represented
originally.

> Just treat 0 as the special
> case. Clarify a comment (which was wrong, when we come via
> device_online() the first time, the online_type would have been 0 /
> MEM_ONLINE). The default is now always MMOP_OFFLINE.

git grep says that you have covered the only remaining place which
hasn't used the enum value.

> This is a preparation to use the online_type as an array index.
> 
> Cc: Greg Kroah-Hartman 
> Cc: Andrew Morton 
> Cc: Michal Hocko 
> Cc: Oscar Salvador 
> Cc: "Rafael J. Wysocki" 
> Cc: Baoquan He 
> Cc: Wei Yang 
> Signed-off-by: David Hildenbrand 

Acked-by: Michal Hocko 

> ---
>  drivers/base/memory.c  | 11 ---
>  include/linux/memory_hotplug.h |  2 +-
>  2 files changed, 5 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index 8c5ce42c0fc3..e7e77cafef80 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -211,17 +211,14 @@ static int memory_subsys_online(struct device *dev)
>   return 0;
>  
>   /*
> -  * If we are called from state_store(), online_type will be
> -  * set >= 0 Otherwise we were called from the device online
> -  * attribute and need to set the online_type.
> +  * When called via device_online() without configuring the online_type,
> +  * we want to default to MMOP_ONLINE.
>*/
> - if (mem->online_type < 0)
> + if (mem->online_type == MMOP_OFFLINE)
>   mem->online_type = MMOP_ONLINE;
>  
>   ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
> -
> - /* clear online_type */
> - mem->online_type = -1;
> + mem->online_type = MMOP_OFFLINE;
>  
>   return ret;
>  }
> diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
> index 261dbf010d5d..c2e06ed5e0e9 100644
> --- a/include/linux/memory_hotplug.h
> +++ b/include/linux/memory_hotplug.h
> @@ -48,7 +48,7 @@ enum {
>  /* Types for control the zone type of onlined and offlined memory */
>  enum {
>   /* Offline the memory. */
> - MMOP_OFFLINE = -1,
> + MMOP_OFFLINE = 0,
>   /* Online the memory. Zone depends, see default_zone_for_pfn(). */
>   MMOP_ONLINE,
>   /* Online the memory to ZONE_NORMAL. */
> -- 
> 2.24.1

-- 
Michal Hocko
SUSE Labs


Re: [PATCH v1 2/5] drivers/base/memory: map MMOP_OFFLINE to 0

2020-03-11 Thread Wei Yang
On Wed, Mar 11, 2020 at 01:30:23PM +0100, David Hildenbrand wrote:
>I have no idea why we have to start at -1. Just treat 0 as the special
>case. Clarify a comment (which was wrong, when we come via
>device_online() the first time, the online_type would have been 0 /
>MEM_ONLINE). The default is now always MMOP_OFFLINE.
>
>This is a preparation to use the online_type as an array index.
>
>Cc: Greg Kroah-Hartman 
>Cc: Andrew Morton 
>Cc: Michal Hocko 
>Cc: Oscar Salvador 
>Cc: "Rafael J. Wysocki" 
>Cc: Baoquan He 
>Cc: Wei Yang 
>Signed-off-by: David Hildenbrand 

Reviewed-by: Wei Yang 

>---
> drivers/base/memory.c  | 11 ---
> include/linux/memory_hotplug.h |  2 +-
> 2 files changed, 5 insertions(+), 8 deletions(-)
>
>diff --git a/drivers/base/memory.c b/drivers/base/memory.c
>index 8c5ce42c0fc3..e7e77cafef80 100644
>--- a/drivers/base/memory.c
>+++ b/drivers/base/memory.c
>@@ -211,17 +211,14 @@ static int memory_subsys_online(struct device *dev)
>   return 0;
> 
>   /*
>-   * If we are called from state_store(), online_type will be
>-   * set >= 0 Otherwise we were called from the device online
>-   * attribute and need to set the online_type.
>+   * When called via device_online() without configuring the online_type,
>+   * we want to default to MMOP_ONLINE.
>*/
>-  if (mem->online_type < 0)
>+  if (mem->online_type == MMOP_OFFLINE)
>   mem->online_type = MMOP_ONLINE;
> 
>   ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
>-
>-  /* clear online_type */
>-  mem->online_type = -1;
>+  mem->online_type = MMOP_OFFLINE;
> 
>   return ret;
> }
>diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
>index 261dbf010d5d..c2e06ed5e0e9 100644
>--- a/include/linux/memory_hotplug.h
>+++ b/include/linux/memory_hotplug.h
>@@ -48,7 +48,7 @@ enum {
> /* Types for control the zone type of onlined and offlined memory */
> enum {
>   /* Offline the memory. */
>-  MMOP_OFFLINE = -1,
>+  MMOP_OFFLINE = 0,
>   /* Online the memory. Zone depends, see default_zone_for_pfn(). */
>   MMOP_ONLINE,
>   /* Online the memory to ZONE_NORMAL. */
>-- 
>2.24.1

-- 
Wei Yang
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