Patchwork [RFC,v4,7/13] memory-hotplug : remove_memory calls __remove_pages

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Submitter Yasuaki Ishimatsu
Date July 18, 2012, 10:12 a.m.
Message ID <50068BF4.1080603@jp.fujitsu.com>
Download mbox | patch
Permalink /patch/171629/
State Not Applicable
Headers show

Comments

Yasuaki Ishimatsu - July 18, 2012, 10:12 a.m.
The patch adds __remove_pages() to remove_memory(). Then the range of
phys_start_pfn argument and nr_pages argument in __remove_pagse() may
have different zone. So zone argument is removed from __remove_pages()
and __remove_pages() caluculates zone in each section.

When CONFIG_SPARSEMEM_VMEMMAP is defined, there is no way to remove a memmap.
So __remove_section only calls unregister_memory_section().

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> 
CC: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>

---
 arch/powerpc/platforms/pseries/hotplug-memory.c |    5 +----
 include/linux/memory_hotplug.h                  |    3 +--
 mm/memory_hotplug.c                             |   19 ++++++++++++-------
 3 files changed, 14 insertions(+), 13 deletions(-)
Bob Liu - July 19, 2012, 8:32 a.m.
On Wed, Jul 18, 2012 at 6:12 PM, Yasuaki Ishimatsu
<isimatu.yasuaki@jp.fujitsu.com> wrote:
> The patch adds __remove_pages() to remove_memory(). Then the range of
> phys_start_pfn argument and nr_pages argument in __remove_pagse() may
> have different zone. So zone argument is removed from __remove_pages()
> and __remove_pages() caluculates zone in each section.
>
> When CONFIG_SPARSEMEM_VMEMMAP is defined, there is no way to remove a memmap.
> So __remove_section only calls unregister_memory_section().
>
> 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>
> CC: Wen Congyang <wency@cn.fujitsu.com>
> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>
> ---
>  arch/powerpc/platforms/pseries/hotplug-memory.c |    5 +----
>  include/linux/memory_hotplug.h                  |    3 +--
>  mm/memory_hotplug.c                             |   19 ++++++++++++-------
>  3 files changed, 14 insertions(+), 13 deletions(-)
>
> Index: linux-3.5-rc6/mm/memory_hotplug.c
> ===================================================================
> --- linux-3.5-rc6.orig/mm/memory_hotplug.c      2012-07-18 18:00:27.440145432 +0900
> +++ linux-3.5-rc6/mm/memory_hotplug.c   2012-07-18 18:01:02.070712487 +0900
> @@ -275,11 +275,14 @@ static int __meminit __add_section(int n
>  #ifdef CONFIG_SPARSEMEM_VMEMMAP
>  static int __remove_section(struct zone *zone, struct mem_section *ms)
>  {
> -       /*
> -        * XXX: Freeing memmap with vmemmap is not implement yet.
> -        *      This should be removed later.
> -        */
> -       return -EBUSY;
> +       int ret = -EINVAL;
> +
> +       if (!valid_section(ms))
> +               return ret;
> +
> +       ret = unregister_memory_section(ms);
> +

I saw a patch from Jiang Liu "mm/hotplug: free zone->pageset when a
zone becomes empty" to
free the zone->pageset and i think there may more cleanup needed when
a zone becomes empty.

We already have __add_zone() in __add_section(), what about add a
function like __remove_zone()
to do the cleanup here?

> +       return ret;
>  }
>  #else
>  static int __remove_section(struct zone *zone, struct mem_section *ms)
> @@ -346,11 +349,11 @@ EXPORT_SYMBOL_GPL(__add_pages);
>   * sure that pages are marked reserved and zones are adjust properly by
>   * calling offline_pages().
>   */
> -int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
> -                unsigned long nr_pages)
> +int __remove_pages(unsigned long phys_start_pfn, unsigned long nr_pages)
>  {
>         unsigned long i, ret = 0;
>         int sections_to_remove;
> +       struct zone *zone;
>
>         /*
>          * We can only remove entire sections
> @@ -363,6 +366,7 @@ int __remove_pages(struct zone *zone, un
>         sections_to_remove = nr_pages / PAGES_PER_SECTION;
>         for (i = 0; i < sections_to_remove; i++) {
>                 unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
> +               zone = page_zone(pfn_to_page(pfn));
>                 ret = __remove_section(zone, __pfn_to_section(pfn));
>                 if (ret)
>                         break;
> @@ -1031,6 +1035,7 @@ int __ref remove_memory(int nid, u64 sta
>         /* remove memmap entry */
>         firmware_map_remove(start, start + size, "System RAM");
>
> +       __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT);
>  out:
>         unlock_memory_hotplug();
>         return ret;
> Index: linux-3.5-rc6/include/linux/memory_hotplug.h
> ===================================================================
> --- linux-3.5-rc6.orig/include/linux/memory_hotplug.h   2012-07-18 18:00:27.445145371 +0900
> +++ linux-3.5-rc6/include/linux/memory_hotplug.h        2012-07-18 18:00:40.461982690 +0900
> @@ -89,8 +89,7 @@ extern bool is_pageblock_removable_noloc
>  /* reasonably generic interface to expand the physical pages in a zone  */
>  extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
>         unsigned long nr_pages);
> -extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
> -       unsigned long nr_pages);
> +extern int __remove_pages(unsigned long start_pfn, unsigned long nr_pages);
>
>  #ifdef CONFIG_NUMA
>  extern int memory_add_physaddr_to_nid(u64 start);
> Index: linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c
> ===================================================================
> --- linux-3.5-rc6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c  2012-07-18 18:00:27.442145407 +0900
> +++ linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c       2012-07-18 18:00:40.470982578 +0900
> @@ -76,7 +76,6 @@ unsigned long memory_block_size_bytes(vo
>  static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
>  {
>         unsigned long start, start_pfn;
> -       struct zone *zone;
>         int i, ret;
>         int sections_to_remove;
>
> @@ -87,8 +86,6 @@ static int pseries_remove_memblock(unsig
>                 return 0;
>         }
>
> -       zone = page_zone(pfn_to_page(start_pfn));
> -
>         /*
>          * Remove section mappings and sysfs entries for the
>          * section of the memory we are removing.
> @@ -101,7 +98,7 @@ static int pseries_remove_memblock(unsig
>         sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
>         for (i = 0; i < sections_to_remove; i++) {
>                 unsigned long pfn = start_pfn + i * PAGES_PER_SECTION;
> -               ret = __remove_pages(zone, start_pfn,  PAGES_PER_SECTION);
> +               ret = __remove_pages(start_pfn,  PAGES_PER_SECTION);
>                 if (ret)
>                         return ret;
>         }
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
Yasuaki Ishimatsu - July 19, 2012, 9:30 a.m.
Hi Bob,

2012/07/19 17:32, Bob Liu wrote:
> On Wed, Jul 18, 2012 at 6:12 PM, Yasuaki Ishimatsu
> <isimatu.yasuaki@jp.fujitsu.com> wrote:
>> The patch adds __remove_pages() to remove_memory(). Then the range of
>> phys_start_pfn argument and nr_pages argument in __remove_pagse() may
>> have different zone. So zone argument is removed from __remove_pages()
>> and __remove_pages() caluculates zone in each section.
>>
>> When CONFIG_SPARSEMEM_VMEMMAP is defined, there is no way to remove a memmap.
>> So __remove_section only calls unregister_memory_section().
>>
>> 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>
>> CC: Wen Congyang <wency@cn.fujitsu.com>
>> Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>>
>> ---
>>   arch/powerpc/platforms/pseries/hotplug-memory.c |    5 +----
>>   include/linux/memory_hotplug.h                  |    3 +--
>>   mm/memory_hotplug.c                             |   19 ++++++++++++-------
>>   3 files changed, 14 insertions(+), 13 deletions(-)
>>
>> Index: linux-3.5-rc6/mm/memory_hotplug.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/mm/memory_hotplug.c      2012-07-18 18:00:27.440145432 +0900
>> +++ linux-3.5-rc6/mm/memory_hotplug.c   2012-07-18 18:01:02.070712487 +0900
>> @@ -275,11 +275,14 @@ static int __meminit __add_section(int n
>>   #ifdef CONFIG_SPARSEMEM_VMEMMAP
>>   static int __remove_section(struct zone *zone, struct mem_section *ms)
>>   {
>> -       /*
>> -        * XXX: Freeing memmap with vmemmap is not implement yet.
>> -        *      This should be removed later.
>> -        */
>> -       return -EBUSY;
>> +       int ret = -EINVAL;
>> +
>> +       if (!valid_section(ms))
>> +               return ret;
>> +
>> +       ret = unregister_memory_section(ms);
>> +
>
> I saw a patch from Jiang Liu "mm/hotplug: free zone->pageset when a
> zone becomes empty" to
> free the zone->pageset and i think there may more cleanup needed when
> a zone becomes empty.
>
> We already have __add_zone() in __add_section(), what about add a
> function like __remove_zone()
> to do the cleanup here?

Thank you for your cooment. As you say, I think cleanup function of zone
is necessary. So I'll update it.

Thanks,
Yasuaki Ishimatsu.

>
>> +       return ret;
>>   }
>>   #else
>>   static int __remove_section(struct zone *zone, struct mem_section *ms)
>> @@ -346,11 +349,11 @@ EXPORT_SYMBOL_GPL(__add_pages);
>>    * sure that pages are marked reserved and zones are adjust properly by
>>    * calling offline_pages().
>>    */
>> -int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
>> -                unsigned long nr_pages)
>> +int __remove_pages(unsigned long phys_start_pfn, unsigned long nr_pages)
>>   {
>>          unsigned long i, ret = 0;
>>          int sections_to_remove;
>> +       struct zone *zone;
>>
>>          /*
>>           * We can only remove entire sections
>> @@ -363,6 +366,7 @@ int __remove_pages(struct zone *zone, un
>>          sections_to_remove = nr_pages / PAGES_PER_SECTION;
>>          for (i = 0; i < sections_to_remove; i++) {
>>                  unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
>> +               zone = page_zone(pfn_to_page(pfn));
>>                  ret = __remove_section(zone, __pfn_to_section(pfn));
>>                  if (ret)
>>                          break;
>> @@ -1031,6 +1035,7 @@ int __ref remove_memory(int nid, u64 sta
>>          /* remove memmap entry */
>>          firmware_map_remove(start, start + size, "System RAM");
>>
>> +       __remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT);
>>   out:
>>          unlock_memory_hotplug();
>>          return ret;
>> Index: linux-3.5-rc6/include/linux/memory_hotplug.h
>> ===================================================================
>> --- linux-3.5-rc6.orig/include/linux/memory_hotplug.h   2012-07-18 18:00:27.445145371 +0900
>> +++ linux-3.5-rc6/include/linux/memory_hotplug.h        2012-07-18 18:00:40.461982690 +0900
>> @@ -89,8 +89,7 @@ extern bool is_pageblock_removable_noloc
>>   /* reasonably generic interface to expand the physical pages in a zone  */
>>   extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
>>          unsigned long nr_pages);
>> -extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
>> -       unsigned long nr_pages);
>> +extern int __remove_pages(unsigned long start_pfn, unsigned long nr_pages);
>>
>>   #ifdef CONFIG_NUMA
>>   extern int memory_add_physaddr_to_nid(u64 start);
>> Index: linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c
>> ===================================================================
>> --- linux-3.5-rc6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c  2012-07-18 18:00:27.442145407 +0900
>> +++ linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c       2012-07-18 18:00:40.470982578 +0900
>> @@ -76,7 +76,6 @@ unsigned long memory_block_size_bytes(vo
>>   static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
>>   {
>>          unsigned long start, start_pfn;
>> -       struct zone *zone;
>>          int i, ret;
>>          int sections_to_remove;
>>
>> @@ -87,8 +86,6 @@ static int pseries_remove_memblock(unsig
>>                  return 0;
>>          }
>>
>> -       zone = page_zone(pfn_to_page(start_pfn));
>> -
>>          /*
>>           * Remove section mappings and sysfs entries for the
>>           * section of the memory we are removing.
>> @@ -101,7 +98,7 @@ static int pseries_remove_memblock(unsig
>>          sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
>>          for (i = 0; i < sections_to_remove; i++) {
>>                  unsigned long pfn = start_pfn + i * PAGES_PER_SECTION;
>> -               ret = __remove_pages(zone, start_pfn,  PAGES_PER_SECTION);
>> +               ret = __remove_pages(start_pfn,  PAGES_PER_SECTION);
>>                  if (ret)
>>                          return ret;
>>          }
>>
>> --
>> To unsubscribe, send a message with 'unsubscribe linux-mm' in
>> the body to majordomo@kvack.org.  For more info on Linux MM,
>> see: http://www.linux-mm.org/ .
>> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
>
>

Patch

Index: linux-3.5-rc6/mm/memory_hotplug.c
===================================================================
--- linux-3.5-rc6.orig/mm/memory_hotplug.c	2012-07-18 18:00:27.440145432 +0900
+++ linux-3.5-rc6/mm/memory_hotplug.c	2012-07-18 18:01:02.070712487 +0900
@@ -275,11 +275,14 @@  static int __meminit __add_section(int n
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 static int __remove_section(struct zone *zone, struct mem_section *ms)
 {
-	/*
-	 * XXX: Freeing memmap with vmemmap is not implement yet.
-	 *      This should be removed later.
-	 */
-	return -EBUSY;
+	int ret = -EINVAL;
+
+	if (!valid_section(ms))
+		return ret;
+
+	ret = unregister_memory_section(ms);
+
+	return ret;
 }
 #else
 static int __remove_section(struct zone *zone, struct mem_section *ms)
@@ -346,11 +349,11 @@  EXPORT_SYMBOL_GPL(__add_pages);
  * sure that pages are marked reserved and zones are adjust properly by
  * calling offline_pages().
  */
-int __remove_pages(struct zone *zone, unsigned long phys_start_pfn,
-		 unsigned long nr_pages)
+int __remove_pages(unsigned long phys_start_pfn, unsigned long nr_pages)
 {
 	unsigned long i, ret = 0;
 	int sections_to_remove;
+	struct zone *zone;
 
 	/*
 	 * We can only remove entire sections
@@ -363,6 +366,7 @@  int __remove_pages(struct zone *zone, un
 	sections_to_remove = nr_pages / PAGES_PER_SECTION;
 	for (i = 0; i < sections_to_remove; i++) {
 		unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION;
+		zone = page_zone(pfn_to_page(pfn));
 		ret = __remove_section(zone, __pfn_to_section(pfn));
 		if (ret)
 			break;
@@ -1031,6 +1035,7 @@  int __ref remove_memory(int nid, u64 sta
 	/* remove memmap entry */
 	firmware_map_remove(start, start + size, "System RAM");
 
+	__remove_pages(start >> PAGE_SHIFT, size >> PAGE_SHIFT);
 out:
 	unlock_memory_hotplug();
 	return ret;
Index: linux-3.5-rc6/include/linux/memory_hotplug.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/memory_hotplug.h	2012-07-18 18:00:27.445145371 +0900
+++ linux-3.5-rc6/include/linux/memory_hotplug.h	2012-07-18 18:00:40.461982690 +0900
@@ -89,8 +89,7 @@  extern bool is_pageblock_removable_noloc
 /* reasonably generic interface to expand the physical pages in a zone  */
 extern int __add_pages(int nid, struct zone *zone, unsigned long start_pfn,
 	unsigned long nr_pages);
-extern int __remove_pages(struct zone *zone, unsigned long start_pfn,
-	unsigned long nr_pages);
+extern int __remove_pages(unsigned long start_pfn, unsigned long nr_pages);
 
 #ifdef CONFIG_NUMA
 extern int memory_add_physaddr_to_nid(u64 start);
Index: linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c
===================================================================
--- linux-3.5-rc6.orig/arch/powerpc/platforms/pseries/hotplug-memory.c	2012-07-18 18:00:27.442145407 +0900
+++ linux-3.5-rc6/arch/powerpc/platforms/pseries/hotplug-memory.c	2012-07-18 18:00:40.470982578 +0900
@@ -76,7 +76,6 @@  unsigned long memory_block_size_bytes(vo
 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
 {
 	unsigned long start, start_pfn;
-	struct zone *zone;
 	int i, ret;
 	int sections_to_remove;
 
@@ -87,8 +86,6 @@  static int pseries_remove_memblock(unsig
 		return 0;
 	}
 
-	zone = page_zone(pfn_to_page(start_pfn));
-
 	/*
 	 * Remove section mappings and sysfs entries for the
 	 * section of the memory we are removing.
@@ -101,7 +98,7 @@  static int pseries_remove_memblock(unsig
 	sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION;
 	for (i = 0; i < sections_to_remove; i++) {
 		unsigned long pfn = start_pfn + i * PAGES_PER_SECTION;
-		ret = __remove_pages(zone, start_pfn,  PAGES_PER_SECTION);
+		ret = __remove_pages(start_pfn,  PAGES_PER_SECTION);
 		if (ret)
 			return ret;
 	}