[PATCH] memory-hotplug: fix not enough check of valid_zones

[PATCH] memory-hotplug: fix not enough check of valid_zones

[Zhang Zhen]

As Yasuaki Ishimatsu described the check here is not enough
if memory has hole as follows:

PFN       0x00          0xd0          0xe0          0xf0
             +-------------+-------------+-------------+
zone type   |   Normal    |     hole    |   Normal    |
             +-------------+-------------+-------------+
In this case, the check can't guarantee that this is "the last
block of memory".
The check of ZONE_MOVABLE has the same problem.

Change the interface name to valid_zones according to most pepole's
suggestion.

Sample output of the sysfs files:
	memory0/valid_zones: none
	memory1/valid_zones: DMA32
	memory2/valid_zones: DMA32
	memory3/valid_zones: DMA32
	memory4/valid_zones: Normal
	memory5/valid_zones: Normal
	memory6/valid_zones: Normal Movable
	memory7/valid_zones: Movable Normal
	memory8/valid_zones: Movable

Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
---
 Documentation/ABI/testing/sysfs-devices-memory |  8 ++---
 Documentation/memory-hotplug.txt               |  4 +--
 drivers/base/memory.c                          | 42 ++++++--------------------
 3 files changed, 15 insertions(+), 39 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory
index 2b2a1d7..deef3b5 100644
--- a/Documentation/ABI/testing/sysfs-devices-memory
+++ b/Documentation/ABI/testing/sysfs-devices-memory
@@ -61,13 +61,13 @@ Users:		hotplug memory remove tools
 		http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils


-What:           /sys/devices/system/memory/memoryX/zones_online_to
+What:           /sys/devices/system/memory/memoryX/valid_zones
 Date:           July 2014
 Contact:	Zhang Zhen <zhenzhang.zhang@huawei.com>
 Description:
-		The file /sys/devices/system/memory/memoryX/zones_online_to
-		is read-only and is designed to show which zone this memory block can
-		be onlined to.
+		The file /sys/devices/system/memory/memoryX/valid_zones	is
+		read-only and is designed to show which zone this memory
+		block can be onlined to.

 What:		/sys/devices/system/memoryX/nodeY
 Date:		October 2009
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
index 5b34e33..947229c 100644
--- a/Documentation/memory-hotplug.txt
+++ b/Documentation/memory-hotplug.txt
@@ -155,7 +155,7 @@ Under each memory block, you can see 4 files:
 /sys/devices/system/memory/memoryXXX/phys_device
 /sys/devices/system/memory/memoryXXX/state
 /sys/devices/system/memory/memoryXXX/removable
-/sys/devices/system/memory/memoryXXX/zones_online_to
+/sys/devices/system/memory/memoryXXX/valid_zones

 'phys_index'      : read-only and contains memory block id, same as XXX.
 'state'           : read-write
@@ -171,7 +171,7 @@ Under each memory block, you can see 4 files:
                     block is removable and a value of 0 indicates that
                     it is not removable. A memory block is removable only if
                     every section in the block is removable.
-'zones_online_to' : read-only: designed to show which zone this memory block
+'valid_zones' : read-only: designed to show which zone this memory block
 		    can be onlined to.

 NOTE:
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index ccaf37c..efd456c 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -374,21 +374,7 @@ static ssize_t show_phys_device(struct device *dev,
 }

 #ifdef CONFIG_MEMORY_HOTREMOVE
-static int __zones_online_to(unsigned long end_pfn,
-				struct page *first_page, unsigned long nr_pages)
-{
-	struct zone *zone_next;
-
-	/* The mem block is the last block of memory. */
-	if (!pfn_valid(end_pfn + 1))
-		return 1;
-	zone_next = page_zone(first_page + nr_pages);
-	if (zone_idx(zone_next) == ZONE_MOVABLE)
-		return 1;
-	return 0;
-}
-
-static ssize_t show_zones_online_to(struct device *dev,
+static ssize_t show_valid_zones(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
@@ -407,33 +393,23 @@ static ssize_t show_zones_online_to(struct device *dev,

 	zone = page_zone(first_page);

-#ifdef CONFIG_HIGHMEM
-	if (zone_idx(zone) == ZONE_HIGHMEM) {
-		if (__zones_online_to(end_pfn, first_page, nr_pages))
+	if (zone_idx(zone) == ZONE_MOVABLE - 1) {
+		/*The mem block is the last memoryblock of this zone.*/
+		if (end_pfn == zone_end_pfn(zone))
 			return sprintf(buf, "%s %s\n",
 					zone->name, (zone + 1)->name);
 	}
-#else
-	if (zone_idx(zone) == ZONE_NORMAL) {
-		if (__zones_online_to(end_pfn, first_page, nr_pages))
-			return sprintf(buf, "%s %s\n",
-					zone->name, (zone + 1)->name);
-	}
-#endif

 	if (zone_idx(zone) == ZONE_MOVABLE) {
-		if (!pfn_valid(start_pfn - nr_pages))
-			return sprintf(buf, "%s %s\n",
-						zone->name, (zone - 1)->name);
-		zone_prev = page_zone(first_page - nr_pages);
-		if (zone_idx(zone_prev) != ZONE_MOVABLE)
+		/*The mem block is the first memoryblock of ZONE_MOVABLE.*/
+		if (start_pfn == zone->zone_start_pfn)
 			return sprintf(buf, "%s %s\n",
-						zone->name, (zone - 1)->name);
+					zone->name, (zone - 1)->name);
 	}

 	return sprintf(buf, "%s\n", zone->name);
 }
-static DEVICE_ATTR(zones_online_to, 0444, show_zones_online_to, NULL);
+static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
 #endif

 static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
@@ -587,7 +563,7 @@ static struct attribute *memory_memblk_attrs[] = {
 	&dev_attr_phys_device.attr,
 	&dev_attr_removable.attr,
 #ifdef CONFIG_MEMORY_HOTREMOVE
-	&dev_attr_zones_online_to.attr,
+	&dev_attr_valid_zones.attr,
 #endif
 	NULL
 };
-- 
1.8.1.4


.




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Re: [PATCH] memory-hotplug: fix not enough check of valid_zones

[Yasuaki Ishimatsu]

(2014/08/26 18:57), Zhang Zhen wrote:
> As Yasuaki Ishimatsu described the check here is not enough
> if memory has hole as follows:
>
> PFN       0x00          0xd0          0xe0          0xf0
>               +-------------+-------------+-------------+
> zone type   |   Normal    |     hole    |   Normal    |
>               +-------------+-------------+-------------+
> In this case, the check can't guarantee that this is "the last
> block of memory".
> The check of ZONE_MOVABLE has the same problem.
>
> Change the interface name to valid_zones according to most pepole's
> suggestion.
>
> Sample output of the sysfs files:
> 	memory0/valid_zones: none
> 	memory1/valid_zones: DMA32
> 	memory2/valid_zones: DMA32
> 	memory3/valid_zones: DMA32
> 	memory4/valid_zones: Normal
> 	memory5/valid_zones: Normal
> 	memory6/valid_zones: Normal Movable
> 	memory7/valid_zones: Movable Normal
> 	memory8/valid_zones: Movable

The patch has two changes:
  - change sysfs interface name
  - change check of ZONE_MOVABLE
So please separate them.

> Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
> ---
>   Documentation/ABI/testing/sysfs-devices-memory |  8 ++---
>   Documentation/memory-hotplug.txt               |  4 +--
>   drivers/base/memory.c                          | 42 ++++++--------------------
>   3 files changed, 15 insertions(+), 39 deletions(-)
>
> diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory
> index 2b2a1d7..deef3b5 100644
> --- a/Documentation/ABI/testing/sysfs-devices-memory
> +++ b/Documentation/ABI/testing/sysfs-devices-memory
> @@ -61,13 +61,13 @@ Users:		hotplug memory remove tools
>   		http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
>
>
> -What:           /sys/devices/system/memory/memoryX/zones_online_to
> +What:           /sys/devices/system/memory/memoryX/valid_zones
>   Date:           July 2014
>   Contact:	Zhang Zhen <zhenzhang.zhang@huawei.com>
>   Description:
> -		The file /sys/devices/system/memory/memoryX/zones_online_to
> -		is read-only and is designed to show which zone this memory block can
> -		be onlined to.
> +		The file /sys/devices/system/memory/memoryX/valid_zones	is
> +		read-only and is designed to show which zone this memory
> +		block can be onlined to.
>
>   What:		/sys/devices/system/memoryX/nodeY
>   Date:		October 2009
> diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
> index 5b34e33..947229c 100644
> --- a/Documentation/memory-hotplug.txt
> +++ b/Documentation/memory-hotplug.txt
> @@ -155,7 +155,7 @@ Under each memory block, you can see 4 files:
>   /sys/devices/system/memory/memoryXXX/phys_device
>   /sys/devices/system/memory/memoryXXX/state
>   /sys/devices/system/memory/memoryXXX/removable
> -/sys/devices/system/memory/memoryXXX/zones_online_to
> +/sys/devices/system/memory/memoryXXX/valid_zones
>
>   'phys_index'      : read-only and contains memory block id, same as XXX.
>   'state'           : read-write
> @@ -171,7 +171,7 @@ Under each memory block, you can see 4 files:
>                       block is removable and a value of 0 indicates that
>                       it is not removable. A memory block is removable only if
>                       every section in the block is removable.
> -'zones_online_to' : read-only: designed to show which zone this memory block
> +'valid_zones' : read-only: designed to show which zone this memory block
>   		    can be onlined to.
>
>   NOTE:
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index ccaf37c..efd456c 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -374,21 +374,7 @@ static ssize_t show_phys_device(struct device *dev,
>   }
>
>   #ifdef CONFIG_MEMORY_HOTREMOVE
> -static int __zones_online_to(unsigned long end_pfn,
> -				struct page *first_page, unsigned long nr_pages)
> -{
> -	struct zone *zone_next;
> -
> -	/* The mem block is the last block of memory. */
> -	if (!pfn_valid(end_pfn + 1))
> -		return 1;
> -	zone_next = page_zone(first_page + nr_pages);
> -	if (zone_idx(zone_next) == ZONE_MOVABLE)
> -		return 1;
> -	return 0;
> -}
> -
> -static ssize_t show_zones_online_to(struct device *dev,
> +static ssize_t show_valid_zones(struct device *dev,
>   				struct device_attribute *attr, char *buf)
>   {
>   	struct memory_block *mem = to_memory_block(dev);
> @@ -407,33 +393,23 @@ static ssize_t show_zones_online_to(struct device *dev,
>
>   	zone = page_zone(first_page);
>
> -#ifdef CONFIG_HIGHMEM
> -	if (zone_idx(zone) == ZONE_HIGHMEM) {
> -		if (__zones_online_to(end_pfn, first_page, nr_pages))
> +	if (zone_idx(zone) == ZONE_MOVABLE - 1) {
> +		/*The mem block is the last memoryblock of this zone.*/
> +		if (end_pfn == zone_end_pfn(zone))
>   			return sprintf(buf, "%s %s\n",
>   					zone->name, (zone + 1)->name);
>   	}
> -#else
> -	if (zone_idx(zone) == ZONE_NORMAL) {
> -		if (__zones_online_to(end_pfn, first_page, nr_pages))
> -			return sprintf(buf, "%s %s\n",
> -					zone->name, (zone + 1)->name);
> -	}
> -#endif
>
>   	if (zone_idx(zone) == ZONE_MOVABLE) {
> -		if (!pfn_valid(start_pfn - nr_pages))
> -			return sprintf(buf, "%s %s\n",
> -						zone->name, (zone - 1)->name);
> -		zone_prev = page_zone(first_page - nr_pages);
> -		if (zone_idx(zone_prev) != ZONE_MOVABLE)
> +		/*The mem block is the first memoryblock of ZONE_MOVABLE.*/

> +		if (start_pfn == zone->zone_start_pfn)
>   			return sprintf(buf, "%s %s\n",
> -						zone->name, (zone - 1)->name);
> +					zone->name, (zone - 1)->name);

How about swap zone->name and (zone - 1)->name.

If swapping them, sample output of the sysfs files shows as follows:
  	memory0/valid_zones: none
  	memory1/valid_zones: DMA32
  	memory2/valid_zones: DMA32
  	memory3/valid_zones: DMA32
  	memory4/valid_zones: Normal
  	memory5/valid_zones: Normal
  	memory6/valid_zones: Normal Movable
  	memory7/valid_zones: Normal Movable
                              ~~~~~~~~~~~~~~
  	memory8/valid_zones: Movable

Thanks,
Yasuaki Ishimatsu

>   	}
>
>   	return sprintf(buf, "%s\n", zone->name);
>   }
> -static DEVICE_ATTR(zones_online_to, 0444, show_zones_online_to, NULL);
> +static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
>   #endif
>
>   static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
> @@ -587,7 +563,7 @@ static struct attribute *memory_memblk_attrs[] = {
>   	&dev_attr_phys_device.attr,
>   	&dev_attr_removable.attr,
>   #ifdef CONFIG_MEMORY_HOTREMOVE
> -	&dev_attr_zones_online_to.attr,
> +	&dev_attr_valid_zones.attr,
>   #endif
>   	NULL
>   };
>


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Re: [PATCH] memory-hotplug: fix not enough check of valid_zones

[Zhang Zhen]

On 2014/8/26 18:23, Yasuaki Ishimatsu wrote:
> (2014/08/26 18:57), Zhang Zhen wrote:
>> As Yasuaki Ishimatsu described the check here is not enough
>> if memory has hole as follows:
>>
>> PFN       0x00          0xd0          0xe0          0xf0
>>               +-------------+-------------+-------------+
>> zone type   |   Normal    |     hole    |   Normal    |
>>               +-------------+-------------+-------------+
>> In this case, the check can't guarantee that this is "the last
>> block of memory".
>> The check of ZONE_MOVABLE has the same problem.
>>
>> Change the interface name to valid_zones according to most pepole's
>> suggestion.
>>
>> Sample output of the sysfs files:
>>     memory0/valid_zones: none
>>     memory1/valid_zones: DMA32
>>     memory2/valid_zones: DMA32
>>     memory3/valid_zones: DMA32
>>     memory4/valid_zones: Normal
>>     memory5/valid_zones: Normal
>>     memory6/valid_zones: Normal Movable
>>     memory7/valid_zones: Movable Normal
>>     memory8/valid_zones: Movable
> 
> The patch has two changes:
>  - change sysfs interface name
>  - change check of ZONE_MOVABLE
> So please separate them.
> 
Ok, i will separate them.

Thanks!
>> Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
>> ---
>>   Documentation/ABI/testing/sysfs-devices-memory |  8 ++---
>>   Documentation/memory-hotplug.txt               |  4 +--
>>   drivers/base/memory.c                          | 42 ++++++--------------------
>>   3 files changed, 15 insertions(+), 39 deletions(-)
>>
>> diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory
>> index 2b2a1d7..deef3b5 100644
>> --- a/Documentation/ABI/testing/sysfs-devices-memory
>> +++ b/Documentation/ABI/testing/sysfs-devices-memory
>> @@ -61,13 +61,13 @@ Users:        hotplug memory remove tools
>>           http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
>>
>>
>> -What:           /sys/devices/system/memory/memoryX/zones_online_to
>> +What:           /sys/devices/system/memory/memoryX/valid_zones
>>   Date:           July 2014
>>   Contact:    Zhang Zhen <zhenzhang.zhang@huawei.com>
>>   Description:
>> -        The file /sys/devices/system/memory/memoryX/zones_online_to
>> -        is read-only and is designed to show which zone this memory block can
>> -        be onlined to.
>> +        The file /sys/devices/system/memory/memoryX/valid_zones    is
>> +        read-only and is designed to show which zone this memory
>> +        block can be onlined to.
>>
>>   What:        /sys/devices/system/memoryX/nodeY
>>   Date:        October 2009
>> diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
>> index 5b34e33..947229c 100644
>> --- a/Documentation/memory-hotplug.txt
>> +++ b/Documentation/memory-hotplug.txt
>> @@ -155,7 +155,7 @@ Under each memory block, you can see 4 files:
>>   /sys/devices/system/memory/memoryXXX/phys_device
>>   /sys/devices/system/memory/memoryXXX/state
>>   /sys/devices/system/memory/memoryXXX/removable
>> -/sys/devices/system/memory/memoryXXX/zones_online_to
>> +/sys/devices/system/memory/memoryXXX/valid_zones
>>
>>   'phys_index'      : read-only and contains memory block id, same as XXX.
>>   'state'           : read-write
>> @@ -171,7 +171,7 @@ Under each memory block, you can see 4 files:
>>                       block is removable and a value of 0 indicates that
>>                       it is not removable. A memory block is removable only if
>>                       every section in the block is removable.
>> -'zones_online_to' : read-only: designed to show which zone this memory block
>> +'valid_zones' : read-only: designed to show which zone this memory block
>>               can be onlined to.
>>
>>   NOTE:
>> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
>> index ccaf37c..efd456c 100644
>> --- a/drivers/base/memory.c
>> +++ b/drivers/base/memory.c
>> @@ -374,21 +374,7 @@ static ssize_t show_phys_device(struct device *dev,
>>   }
>>
>>   #ifdef CONFIG_MEMORY_HOTREMOVE
>> -static int __zones_online_to(unsigned long end_pfn,
>> -                struct page *first_page, unsigned long nr_pages)
>> -{
>> -    struct zone *zone_next;
>> -
>> -    /* The mem block is the last block of memory. */
>> -    if (!pfn_valid(end_pfn + 1))
>> -        return 1;
>> -    zone_next = page_zone(first_page + nr_pages);
>> -    if (zone_idx(zone_next) == ZONE_MOVABLE)
>> -        return 1;
>> -    return 0;
>> -}
>> -
>> -static ssize_t show_zones_online_to(struct device *dev,
>> +static ssize_t show_valid_zones(struct device *dev,
>>                   struct device_attribute *attr, char *buf)
>>   {
>>       struct memory_block *mem = to_memory_block(dev);
>> @@ -407,33 +393,23 @@ static ssize_t show_zones_online_to(struct device *dev,
>>
>>       zone = page_zone(first_page);
>>
>> -#ifdef CONFIG_HIGHMEM
>> -    if (zone_idx(zone) == ZONE_HIGHMEM) {
>> -        if (__zones_online_to(end_pfn, first_page, nr_pages))
>> +    if (zone_idx(zone) == ZONE_MOVABLE - 1) {
>> +        /*The mem block is the last memoryblock of this zone.*/
>> +        if (end_pfn == zone_end_pfn(zone))
>>               return sprintf(buf, "%s %s\n",
>>                       zone->name, (zone + 1)->name);
>>       }
>> -#else
>> -    if (zone_idx(zone) == ZONE_NORMAL) {
>> -        if (__zones_online_to(end_pfn, first_page, nr_pages))
>> -            return sprintf(buf, "%s %s\n",
>> -                    zone->name, (zone + 1)->name);
>> -    }
>> -#endif
>>
>>       if (zone_idx(zone) == ZONE_MOVABLE) {
>> -        if (!pfn_valid(start_pfn - nr_pages))
>> -            return sprintf(buf, "%s %s\n",
>> -                        zone->name, (zone - 1)->name);
>> -        zone_prev = page_zone(first_page - nr_pages);
>> -        if (zone_idx(zone_prev) != ZONE_MOVABLE)
>> +        /*The mem block is the first memoryblock of ZONE_MOVABLE.*/
> 
>> +        if (start_pfn == zone->zone_start_pfn)
>>               return sprintf(buf, "%s %s\n",
>> -                        zone->name, (zone - 1)->name);
>> +                    zone->name, (zone - 1)->name);
> 
> How about swap zone->name and (zone - 1)->name.
> 
> If swapping them, sample output of the sysfs files shows as follows:
>      memory0/valid_zones: none
>      memory1/valid_zones: DMA32
>      memory2/valid_zones: DMA32
>      memory3/valid_zones: DMA32
>      memory4/valid_zones: Normal
>      memory5/valid_zones: Normal
>      memory6/valid_zones: Normal Movable
>      memory7/valid_zones: Normal Movable
> 
	memory6/valid_zones: Normal Movable
	memory7/valid_zones: Movable Normal
Here can better show the dividing line between ZONE_MOVABLE and ZONE_NORMAL.

The first column shows it's default zone,
for memory6:
	the first column Normal shows that it can be onlined to ZONE_NORMAL by default.
	echo offline > memory6/state
	echo online > memory6/state
	the second column Movable shows that it can be onlined to ZONE_MOVABLE by online_movable.
	echo offline > memory6/state
	echo online_movable > memory6/state
for memory7:
	the first column Movable shows that it can be onlined to ZONE_MOVABLE by default.
	echo offline > memory7/state
	echo online > memory7/state
	the second column Normal shows that it can be onlined to ZONE_NORMAL by online_kernel.
	echo offline > memory7/state
	echo online_kernel > memory7/state

And it is more convenient for script to work.
So i think we should leave it as it is.

Thanks!
                             ~~~~~~~~~~~~~~
>      memory8/valid_zones: Movable
> 
> Thanks,
> Yasuaki Ishimatsu
> 
>>       }
>>
>>       return sprintf(buf, "%s\n", zone->name);
>>   }
>> -static DEVICE_ATTR(zones_online_to, 0444, show_zones_online_to, NULL);
>> +static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
>>   #endif
>>
>>   static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
>> @@ -587,7 +563,7 @@ static struct attribute *memory_memblk_attrs[] = {
>>       &dev_attr_phys_device.attr,
>>       &dev_attr_removable.attr,
>>   #ifdef CONFIG_MEMORY_HOTREMOVE
>> -    &dev_attr_zones_online_to.attr,
>> +    &dev_attr_valid_zones.attr,
>>   #endif
>>       NULL
>>   };
>>
> 
> 
> 
> .
> 


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Re: [PATCH] memory-hotplug: fix not enough check of valid_zones

[Yasuaki Ishimatsu]

(2014/08/27 10:55), Zhang Zhen wrote:
> On 2014/8/26 18:23, Yasuaki Ishimatsu wrote:
>> (2014/08/26 18:57), Zhang Zhen wrote:
>>> As Yasuaki Ishimatsu described the check here is not enough
>>> if memory has hole as follows:
>>>
>>> PFN       0x00          0xd0          0xe0          0xf0
>>>                +-------------+-------------+-------------+
>>> zone type   |   Normal    |     hole    |   Normal    |
>>>                +-------------+-------------+-------------+
>>> In this case, the check can't guarantee that this is "the last
>>> block of memory".
>>> The check of ZONE_MOVABLE has the same problem.
>>>
>>> Change the interface name to valid_zones according to most pepole's
>>> suggestion.
>>>
>>> Sample output of the sysfs files:
>>>      memory0/valid_zones: none
>>>      memory1/valid_zones: DMA32
>>>      memory2/valid_zones: DMA32
>>>      memory3/valid_zones: DMA32
>>>      memory4/valid_zones: Normal
>>>      memory5/valid_zones: Normal
>>>      memory6/valid_zones: Normal Movable
>>>      memory7/valid_zones: Movable Normal
>>>      memory8/valid_zones: Movable
>>
>> The patch has two changes:
>>   - change sysfs interface name
>>   - change check of ZONE_MOVABLE
>> So please separate them.
>>
> Ok, i will separate them.
>
> Thanks!
>>> Signed-off-by: Zhang Zhen <zhenzhang.zhang@huawei.com>
>>> ---
>>>    Documentation/ABI/testing/sysfs-devices-memory |  8 ++---
>>>    Documentation/memory-hotplug.txt               |  4 +--
>>>    drivers/base/memory.c                          | 42 ++++++--------------------
>>>    3 files changed, 15 insertions(+), 39 deletions(-)
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory
>>> index 2b2a1d7..deef3b5 100644
>>> --- a/Documentation/ABI/testing/sysfs-devices-memory
>>> +++ b/Documentation/ABI/testing/sysfs-devices-memory
>>> @@ -61,13 +61,13 @@ Users:        hotplug memory remove tools
>>>            http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils
>>>
>>>
>>> -What:           /sys/devices/system/memory/memoryX/zones_online_to
>>> +What:           /sys/devices/system/memory/memoryX/valid_zones
>>>    Date:           July 2014
>>>    Contact:    Zhang Zhen <zhenzhang.zhang@huawei.com>
>>>    Description:
>>> -        The file /sys/devices/system/memory/memoryX/zones_online_to
>>> -        is read-only and is designed to show which zone this memory block can
>>> -        be onlined to.
>>> +        The file /sys/devices/system/memory/memoryX/valid_zones    is
>>> +        read-only and is designed to show which zone this memory
>>> +        block can be onlined to.
>>>
>>>    What:        /sys/devices/system/memoryX/nodeY
>>>    Date:        October 2009
>>> diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt
>>> index 5b34e33..947229c 100644
>>> --- a/Documentation/memory-hotplug.txt
>>> +++ b/Documentation/memory-hotplug.txt
>>> @@ -155,7 +155,7 @@ Under each memory block, you can see 4 files:
>>>    /sys/devices/system/memory/memoryXXX/phys_device
>>>    /sys/devices/system/memory/memoryXXX/state
>>>    /sys/devices/system/memory/memoryXXX/removable
>>> -/sys/devices/system/memory/memoryXXX/zones_online_to
>>> +/sys/devices/system/memory/memoryXXX/valid_zones
>>>
>>>    'phys_index'      : read-only and contains memory block id, same as XXX.
>>>    'state'           : read-write
>>> @@ -171,7 +171,7 @@ Under each memory block, you can see 4 files:
>>>                        block is removable and a value of 0 indicates that
>>>                        it is not removable. A memory block is removable only if
>>>                        every section in the block is removable.
>>> -'zones_online_to' : read-only: designed to show which zone this memory block
>>> +'valid_zones' : read-only: designed to show which zone this memory block
>>>                can be onlined to.
>>>
>>>    NOTE:
>>> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
>>> index ccaf37c..efd456c 100644
>>> --- a/drivers/base/memory.c
>>> +++ b/drivers/base/memory.c
>>> @@ -374,21 +374,7 @@ static ssize_t show_phys_device(struct device *dev,
>>>    }
>>>
>>>    #ifdef CONFIG_MEMORY_HOTREMOVE
>>> -static int __zones_online_to(unsigned long end_pfn,
>>> -                struct page *first_page, unsigned long nr_pages)
>>> -{
>>> -    struct zone *zone_next;
>>> -
>>> -    /* The mem block is the last block of memory. */
>>> -    if (!pfn_valid(end_pfn + 1))
>>> -        return 1;
>>> -    zone_next = page_zone(first_page + nr_pages);
>>> -    if (zone_idx(zone_next) == ZONE_MOVABLE)
>>> -        return 1;
>>> -    return 0;
>>> -}
>>> -
>>> -static ssize_t show_zones_online_to(struct device *dev,
>>> +static ssize_t show_valid_zones(struct device *dev,
>>>                    struct device_attribute *attr, char *buf)
>>>    {
>>>        struct memory_block *mem = to_memory_block(dev);
>>> @@ -407,33 +393,23 @@ static ssize_t show_zones_online_to(struct device *dev,
>>>
>>>        zone = page_zone(first_page);
>>>
>>> -#ifdef CONFIG_HIGHMEM
>>> -    if (zone_idx(zone) == ZONE_HIGHMEM) {
>>> -        if (__zones_online_to(end_pfn, first_page, nr_pages))
>>> +    if (zone_idx(zone) == ZONE_MOVABLE - 1) {
>>> +        /*The mem block is the last memoryblock of this zone.*/
>>> +        if (end_pfn == zone_end_pfn(zone))
>>>                return sprintf(buf, "%s %s\n",
>>>                        zone->name, (zone + 1)->name);
>>>        }
>>> -#else
>>> -    if (zone_idx(zone) == ZONE_NORMAL) {
>>> -        if (__zones_online_to(end_pfn, first_page, nr_pages))
>>> -            return sprintf(buf, "%s %s\n",
>>> -                    zone->name, (zone + 1)->name);
>>> -    }
>>> -#endif
>>>
>>>        if (zone_idx(zone) == ZONE_MOVABLE) {
>>> -        if (!pfn_valid(start_pfn - nr_pages))
>>> -            return sprintf(buf, "%s %s\n",
>>> -                        zone->name, (zone - 1)->name);
>>> -        zone_prev = page_zone(first_page - nr_pages);
>>> -        if (zone_idx(zone_prev) != ZONE_MOVABLE)
>>> +        /*The mem block is the first memoryblock of ZONE_MOVABLE.*/
>>
>>> +        if (start_pfn == zone->zone_start_pfn)
>>>                return sprintf(buf, "%s %s\n",
>>> -                        zone->name, (zone - 1)->name);
>>> +                    zone->name, (zone - 1)->name);
>>
>> How about swap zone->name and (zone - 1)->name.
>>
>> If swapping them, sample output of the sysfs files shows as follows:
>>       memory0/valid_zones: none
>>       memory1/valid_zones: DMA32
>>       memory2/valid_zones: DMA32
>>       memory3/valid_zones: DMA32
>>       memory4/valid_zones: Normal
>>       memory5/valid_zones: Normal
>>       memory6/valid_zones: Normal Movable
>>       memory7/valid_zones: Normal Movable
>>
> 	memory6/valid_zones: Normal Movable
> 	memory7/valid_zones: Movable Normal
> Here can better show the dividing line between ZONE_MOVABLE and ZONE_NORMAL.
>

> The first column shows it's default zone,

If so, please write the information in 'valid_zones' term
of memory-hotplug.txt. Nobody know it.

Thanks,
Yasuaki Ishimatasu

> for memory6:
> 	the first column Normal shows that it can be onlined to ZONE_NORMAL by default.
> 	echo offline > memory6/state
> 	echo online > memory6/state
> 	the second column Movable shows that it can be onlined to ZONE_MOVABLE by online_movable.
> 	echo offline > memory6/state
> 	echo online_movable > memory6/state
> for memory7:
> 	the first column Movable shows that it can be onlined to ZONE_MOVABLE by default.
> 	echo offline > memory7/state
> 	echo online > memory7/state
> 	the second column Normal shows that it can be onlined to ZONE_NORMAL by online_kernel.
> 	echo offline > memory7/state
> 	echo online_kernel > memory7/state
>
> And it is more convenient for script to work.
> So i think we should leave it as it is.
>
> Thanks!
>                               ~~~~~~~~~~~~~~
>>       memory8/valid_zones: Movable
>>
>> Thanks,
>> Yasuaki Ishimatsu
>>
>>>        }
>>>
>>>        return sprintf(buf, "%s\n", zone->name);
>>>    }
>>> -static DEVICE_ATTR(zones_online_to, 0444, show_zones_online_to, NULL);
>>> +static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
>>>    #endif
>>>
>>>    static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
>>> @@ -587,7 +563,7 @@ static struct attribute *memory_memblk_attrs[] = {
>>>        &dev_attr_phys_device.attr,
>>>        &dev_attr_removable.attr,
>>>    #ifdef CONFIG_MEMORY_HOTREMOVE
>>> -    &dev_attr_zones_online_to.attr,
>>> +    &dev_attr_valid_zones.attr,
>>>    #endif
>>>        NULL
>>>    };
>>>
>>
>>
>>
>> .
>>
>
>


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