[v1,2/5] drivers/base/memory: map MMOP_OFFLINE to 0
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Message ID 20200311123026.16071-3-david@redhat.com
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Commit 3956c6e9e075d54f4e7aaba43cf7486872bdca0c
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  • [v1,1/5] drivers/base/memory: rename MMOP_ONLINE_KEEP to MMOP_ONLINE
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Commit Message

David Hildenbrand March 11, 2020, 12:30 p.m. UTC
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 <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 drivers/base/memory.c          | 11 ++++-------
 include/linux/memory_hotplug.h |  2 +-
 2 files changed, 5 insertions(+), 8 deletions(-)

Comments

Wei Yang March 11, 2020, 2:18 p.m. UTC | #1
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 <gregkh@linuxfoundation.org>
>Cc: Andrew Morton <akpm@linux-foundation.org>
>Cc: Michal Hocko <mhocko@kernel.org>
>Cc: Oscar Salvador <osalvador@suse.de>
>Cc: "Rafael J. Wysocki" <rafael@kernel.org>
>Cc: Baoquan He <bhe@redhat.com>
>Cc: Wei Yang <richard.weiyang@gmail.com>
>Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Wei Yang <richard.weiyang@gmail.com>

>---
> 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 March 16, 2020, 3:19 p.m. UTC | #2
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 <gregkh@linuxfoundation.org>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Michal Hocko <mhocko@kernel.org>
> Cc: Oscar Salvador <osalvador@suse.de>
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Baoquan He <bhe@redhat.com>
> Cc: Wei Yang <richard.weiyang@gmail.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  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

Patch
diff mbox series

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. */