Patchwork [RFC,10/12] memory-hotplug : free memmap of sparse-vmemmap

login
register
mail settings
Submitter Yasuaki Ishimatsu
Date June 27, 2012, 5:56 a.m.
Message ID <4FEAA09F.5000907@jp.fujitsu.com>
Download mbox | patch
Permalink /patch/167555/
State Not Applicable
Headers show

Comments

Yasuaki Ishimatsu - June 27, 2012, 5:56 a.m.
I don't think that all pages of virtual mapping in removed memory can be
freed, since page which type is MIX_SECTION_INFO is difficult to free.
So, the patch only frees page which type is SECTION_INFO at first.

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/x86/mm/init_64.c |   89 ++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mm.h    |    2 +
 mm/memory_hotplug.c   |    5 ++
 mm/sparse.c           |    5 +-
 4 files changed, 99 insertions(+), 2 deletions(-)
Jiang Liu - June 30, 2012, 3:58 p.m.
On 06/27/2012 01:56 PM, Yasuaki Ishimatsu wrote:
> I don't think that all pages of virtual mapping in removed memory can be
> freed, since page which type is MIX_SECTION_INFO is difficult to free.
> So, the patch only frees page which type is SECTION_INFO at first.
> 
> 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/x86/mm/init_64.c |   89 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mm.h    |    2 +
>  mm/memory_hotplug.c   |    5 ++
>  mm/sparse.c           |    5 +-
>  4 files changed, 99 insertions(+), 2 deletions(-)
> 
> Index: linux-3.5-rc4/include/linux/mm.h
> ===================================================================
> --- linux-3.5-rc4.orig/include/linux/mm.h	2012-06-27 09:11:13.790150442 +0900
> +++ linux-3.5-rc4/include/linux/mm.h	2012-06-27 09:11:16.433117400 +0900
> @@ -1588,6 +1588,8 @@ int vmemmap_populate(struct page *start_
>  void vmemmap_populate_print_last(void);
>  void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
>  				  unsigned long size);
> +void vmemmap_kfree(struct page *memmpa, unsigned long nr_pages);
> +void vmemmap_free_bootmem(struct page *memmpa, unsigned long nr_pages);
> 
>  enum mf_flags {
>  	MF_COUNT_INCREASED = 1 << 0,
> Index: linux-3.5-rc4/mm/sparse.c
> ===================================================================
> --- linux-3.5-rc4.orig/mm/sparse.c	2012-06-27 09:06:35.317631878 +0900
> +++ linux-3.5-rc4/mm/sparse.c	2012-06-27 09:11:16.434117388 +0900
> @@ -614,12 +614,13 @@ static inline struct page *kmalloc_secti
>  	/* This will make the necessary allocations eventually. */
>  	return sparse_mem_map_populate(pnum, nid);
>  }
> -static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
> +static void __kfree_section_memmap(struct page *page, unsigned long nr_pages)
>  {
> -	return; /* XXX: Not implemented yet */
> +	vmemmap_kfree(page, nr_pages);
>  }
>  static void free_map_bootmem(struct page *page, unsigned long nr_pages)
>  {
> +	vmemmap_free_bootmem(page, nr_pages);
>  }
>  #else
>  static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
> Index: linux-3.5-rc4/arch/x86/mm/init_64.c
> ===================================================================
> --- linux-3.5-rc4.orig/arch/x86/mm/init_64.c	2012-06-27 09:11:13.791150430 +0900
> +++ linux-3.5-rc4/arch/x86/mm/init_64.c	2012-06-27 09:11:59.254581998 +0900
> @@ -978,6 +978,95 @@ vmemmap_populate(struct page *start_page
>  	return 0;
>  }
> 
> +unsigned long find_and_clear_pte_page(unsigned long addr, unsigned long end,
> +				      struct page *page)
I think the third parameter should be "struct page **pp" instead of "struct page *page".
And "page = pte_page(*pte)" should be "*pp = pte_page(*pte)".
Otherwise the found page pointer can't be returned to the caller and vmemmap_kfree()
just sees random value in variable "page".

> +{
> +	pgd_t *pgd;
> +	pud_t *pud;
> +	pmd_t *pmd;
> +	pte_t *pte;
> +	unsigned long next;
> +
> +	page = NULL;
> +
> +	pgd = pgd_offset_k(addr);
> +	if (pgd_none(*pgd))
> +		return PAGE_SIZE;
> +
> +	pud = pud_offset(pgd, addr);
> +	if (pud_none(*pud))
> +		return PAGE_SIZE;
> +
> +	if (!cpu_has_pse) {
> +		next = (addr + PAGE_SIZE) & PAGE_MASK;
> +		pmd = pmd_offset(pud, addr);
> +		if (pmd_none(*pmd))
> +			return next;
> +
> +		pte = pte_offset_kernel(pmd, addr);
> +		if (pte_none(*pte))
> +			return next;
> +
> +		page = pte_page(*pte);
> +		pte_clear(&init_mm, addr, pte);
> +	} else {
> +		next = pmd_addr_end(addr, end);
> +
> +		pmd = pmd_offset(pud, addr);
> +		if (pmd_none(*pmd))
> +			return next;
> +
> +		page = pmd_page(*pmd);
> +		pmd_clear(pmd);
> +	}
> +
> +	return next;
> +}
> +
> +void __meminit
> +vmemmap_kfree(struct page *memmap, unsigned long nr_pages)
> +{
> +	unsigned long addr = (unsigned long)memmap;
> +	unsigned long end = (unsigned long)(memmap + nr_pages);
> +	unsigned long next;
> +	unsigned int order;
> +	struct page *page;
> +
> +	for (; addr < end; addr = next) {
> +		next = find_and_clear_pte_page(addr, end, page);
> +		if (!page)
> +			continue;
> +
> +		if (is_vmalloc_addr(page))
> +			vfree(page);
> +		else {
> +			order = next - addr;
> +			free_pages((unsigned long)page,
> +				   get_order(sizeof(struct page) *  order));
> +		}
> +	}
> +}
> +
> +void __meminit
> +vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages)
> +{
> +	unsigned long addr = (unsigned long)memmap;
> +	unsigned long end = (unsigned long)(memmap + nr_pages);
> +	unsigned long next;
> +	struct page *page;
> +	unsigned long magic;
> +
> +	for (; addr < end; addr = next) {
> +		next = find_and_clear_pte_page(addr, end, page);
> +		if (!page)
> +			continue;
> +
> +		magic = (unsigned long) page->lru.next;
> +		if (magic == SECTION_INFO)
> +			put_page_bootmem(page);
> +	}
> +}
> +
>  void __meminit
>  register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page,
>  			     unsigned long size)
> Index: linux-3.5-rc4/mm/memory_hotplug.c
> ===================================================================
> --- linux-3.5-rc4.orig/mm/memory_hotplug.c	2012-06-27 09:11:13.789150454 +0900
> +++ linux-3.5-rc4/mm/memory_hotplug.c	2012-06-27 09:11:16.436117363 +0900
> @@ -303,6 +303,8 @@ static int __meminit __add_section(int n
>  #ifdef CONFIG_SPARSEMEM_VMEMMAP
>  static int __remove_section(struct zone *zone, struct mem_section *ms)
>  {
> +	unsigned long flags;
> +	struct pglist_data *pgdat = zone->zone_pgdat;
>  	int ret;
> 
>  	if (!valid_section(ms))
> @@ -310,6 +312,9 @@ static int __remove_section(struct zone
> 
>  	ret = unregister_memory_section(ms);
> 
> +	pgdat_resize_lock(pgdat, &flags);
> +	sparse_remove_one_section(zone, ms);
> +	pgdat_resize_unlock(pgdat, &flags);
>  	return ret;
>  }
>  #else
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
Yasuaki Ishimatsu - July 2, 2012, 3:01 a.m.
Hi Jiang,

2012/07/01 0:58, Jiang Liu wrote:
> On 06/27/2012 01:56 PM, Yasuaki Ishimatsu wrote:
>> I don't think that all pages of virtual mapping in removed memory can be
>> freed, since page which type is MIX_SECTION_INFO is difficult to free.
>> So, the patch only frees page which type is SECTION_INFO at first.
>>
>> 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/x86/mm/init_64.c |   89 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>   include/linux/mm.h    |    2 +
>>   mm/memory_hotplug.c   |    5 ++
>>   mm/sparse.c           |    5 +-
>>   4 files changed, 99 insertions(+), 2 deletions(-)
>>
>> Index: linux-3.5-rc4/include/linux/mm.h
>> ===================================================================
>> --- linux-3.5-rc4.orig/include/linux/mm.h	2012-06-27 09:11:13.790150442 +0900
>> +++ linux-3.5-rc4/include/linux/mm.h	2012-06-27 09:11:16.433117400 +0900
>> @@ -1588,6 +1588,8 @@ int vmemmap_populate(struct page *start_
>>   void vmemmap_populate_print_last(void);
>>   void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
>>   				  unsigned long size);
>> +void vmemmap_kfree(struct page *memmpa, unsigned long nr_pages);
>> +void vmemmap_free_bootmem(struct page *memmpa, unsigned long nr_pages);
>>
>>   enum mf_flags {
>>   	MF_COUNT_INCREASED = 1 << 0,
>> Index: linux-3.5-rc4/mm/sparse.c
>> ===================================================================
>> --- linux-3.5-rc4.orig/mm/sparse.c	2012-06-27 09:06:35.317631878 +0900
>> +++ linux-3.5-rc4/mm/sparse.c	2012-06-27 09:11:16.434117388 +0900
>> @@ -614,12 +614,13 @@ static inline struct page *kmalloc_secti
>>   	/* This will make the necessary allocations eventually. */
>>   	return sparse_mem_map_populate(pnum, nid);
>>   }
>> -static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
>> +static void __kfree_section_memmap(struct page *page, unsigned long nr_pages)
>>   {
>> -	return; /* XXX: Not implemented yet */
>> +	vmemmap_kfree(page, nr_pages);
>>   }
>>   static void free_map_bootmem(struct page *page, unsigned long nr_pages)
>>   {
>> +	vmemmap_free_bootmem(page, nr_pages);
>>   }
>>   #else
>>   static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
>> Index: linux-3.5-rc4/arch/x86/mm/init_64.c
>> ===================================================================
>> --- linux-3.5-rc4.orig/arch/x86/mm/init_64.c	2012-06-27 09:11:13.791150430 +0900
>> +++ linux-3.5-rc4/arch/x86/mm/init_64.c	2012-06-27 09:11:59.254581998 +0900
>> @@ -978,6 +978,95 @@ vmemmap_populate(struct page *start_page
>>   	return 0;
>>   }
>>
>> +unsigned long find_and_clear_pte_page(unsigned long addr, unsigned long end,
>> +				      struct page *page)
> I think the third parameter should be "struct page **pp" instead of "struct page *page".
> And "page = pte_page(*pte)" should be "*pp = pte_page(*pte)".
> Otherwise the found page pointer can't be returned to the caller and vmemmap_kfree()
> just sees random value in variable "page".

Oh, you are right. I'll update it.

Thanks,
Yasuaki Ishimatsu

>> +{
>> +	pgd_t *pgd;
>> +	pud_t *pud;
>> +	pmd_t *pmd;
>> +	pte_t *pte;
>> +	unsigned long next;
>> +
>> +	page = NULL;
>> +
>> +	pgd = pgd_offset_k(addr);
>> +	if (pgd_none(*pgd))
>> +		return PAGE_SIZE;
>> +
>> +	pud = pud_offset(pgd, addr);
>> +	if (pud_none(*pud))
>> +		return PAGE_SIZE;
>> +
>> +	if (!cpu_has_pse) {
>> +		next = (addr + PAGE_SIZE) & PAGE_MASK;
>> +		pmd = pmd_offset(pud, addr);
>> +		if (pmd_none(*pmd))
>> +			return next;
>> +
>> +		pte = pte_offset_kernel(pmd, addr);
>> +		if (pte_none(*pte))
>> +			return next;
>> +
>> +		page = pte_page(*pte);
>> +		pte_clear(&init_mm, addr, pte);
>> +	} else {
>> +		next = pmd_addr_end(addr, end);
>> +
>> +		pmd = pmd_offset(pud, addr);
>> +		if (pmd_none(*pmd))
>> +			return next;
>> +
>> +		page = pmd_page(*pmd);
>> +		pmd_clear(pmd);
>> +	}
>> +
>> +	return next;
>> +}
>> +
>> +void __meminit
>> +vmemmap_kfree(struct page *memmap, unsigned long nr_pages)
>> +{
>> +	unsigned long addr = (unsigned long)memmap;
>> +	unsigned long end = (unsigned long)(memmap + nr_pages);
>> +	unsigned long next;
>> +	unsigned int order;
>> +	struct page *page;
>> +
>> +	for (; addr < end; addr = next) {
>> +		next = find_and_clear_pte_page(addr, end, page);
>> +		if (!page)
>> +			continue;
>> +
>> +		if (is_vmalloc_addr(page))
>> +			vfree(page);
>> +		else {
>> +			order = next - addr;
>> +			free_pages((unsigned long)page,
>> +				   get_order(sizeof(struct page) *  order));
>> +		}
>> +	}
>> +}
>> +
>> +void __meminit
>> +vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages)
>> +{
>> +	unsigned long addr = (unsigned long)memmap;
>> +	unsigned long end = (unsigned long)(memmap + nr_pages);
>> +	unsigned long next;
>> +	struct page *page;
>> +	unsigned long magic;
>> +
>> +	for (; addr < end; addr = next) {
>> +		next = find_and_clear_pte_page(addr, end, page);
>> +		if (!page)
>> +			continue;
>> +
>> +		magic = (unsigned long) page->lru.next;
>> +		if (magic == SECTION_INFO)
>> +			put_page_bootmem(page);
>> +	}
>> +}
>> +
>>   void __meminit
>>   register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page,
>>   			     unsigned long size)
>> Index: linux-3.5-rc4/mm/memory_hotplug.c
>> ===================================================================
>> --- linux-3.5-rc4.orig/mm/memory_hotplug.c	2012-06-27 09:11:13.789150454 +0900
>> +++ linux-3.5-rc4/mm/memory_hotplug.c	2012-06-27 09:11:16.436117363 +0900
>> @@ -303,6 +303,8 @@ static int __meminit __add_section(int n
>>   #ifdef CONFIG_SPARSEMEM_VMEMMAP
>>   static int __remove_section(struct zone *zone, struct mem_section *ms)
>>   {
>> +	unsigned long flags;
>> +	struct pglist_data *pgdat = zone->zone_pgdat;
>>   	int ret;
>>
>>   	if (!valid_section(ms))
>> @@ -310,6 +312,9 @@ static int __remove_section(struct zone
>>
>>   	ret = unregister_memory_section(ms);
>>
>> +	pgdat_resize_lock(pgdat, &flags);
>> +	sparse_remove_one_section(zone, ms);
>> +	pgdat_resize_unlock(pgdat, &flags);
>>   	return ret;
>>   }
>>   #else
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
> 
> 
> --
> 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-rc4/include/linux/mm.h
===================================================================
--- linux-3.5-rc4.orig/include/linux/mm.h	2012-06-27 09:11:13.790150442 +0900
+++ linux-3.5-rc4/include/linux/mm.h	2012-06-27 09:11:16.433117400 +0900
@@ -1588,6 +1588,8 @@  int vmemmap_populate(struct page *start_
 void vmemmap_populate_print_last(void);
 void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
 				  unsigned long size);
+void vmemmap_kfree(struct page *memmpa, unsigned long nr_pages);
+void vmemmap_free_bootmem(struct page *memmpa, unsigned long nr_pages);

 enum mf_flags {
 	MF_COUNT_INCREASED = 1 << 0,
Index: linux-3.5-rc4/mm/sparse.c
===================================================================
--- linux-3.5-rc4.orig/mm/sparse.c	2012-06-27 09:06:35.317631878 +0900
+++ linux-3.5-rc4/mm/sparse.c	2012-06-27 09:11:16.434117388 +0900
@@ -614,12 +614,13 @@  static inline struct page *kmalloc_secti
 	/* This will make the necessary allocations eventually. */
 	return sparse_mem_map_populate(pnum, nid);
 }
-static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
+static void __kfree_section_memmap(struct page *page, unsigned long nr_pages)
 {
-	return; /* XXX: Not implemented yet */
+	vmemmap_kfree(page, nr_pages);
 }
 static void free_map_bootmem(struct page *page, unsigned long nr_pages)
 {
+	vmemmap_free_bootmem(page, nr_pages);
 }
 #else
 static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
Index: linux-3.5-rc4/arch/x86/mm/init_64.c
===================================================================
--- linux-3.5-rc4.orig/arch/x86/mm/init_64.c	2012-06-27 09:11:13.791150430 +0900
+++ linux-3.5-rc4/arch/x86/mm/init_64.c	2012-06-27 09:11:59.254581998 +0900
@@ -978,6 +978,95 @@  vmemmap_populate(struct page *start_page
 	return 0;
 }

+unsigned long find_and_clear_pte_page(unsigned long addr, unsigned long end,
+				      struct page *page)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	unsigned long next;
+
+	page = NULL;
+
+	pgd = pgd_offset_k(addr);
+	if (pgd_none(*pgd))
+		return PAGE_SIZE;
+
+	pud = pud_offset(pgd, addr);
+	if (pud_none(*pud))
+		return PAGE_SIZE;
+
+	if (!cpu_has_pse) {
+		next = (addr + PAGE_SIZE) & PAGE_MASK;
+		pmd = pmd_offset(pud, addr);
+		if (pmd_none(*pmd))
+			return next;
+
+		pte = pte_offset_kernel(pmd, addr);
+		if (pte_none(*pte))
+			return next;
+
+		page = pte_page(*pte);
+		pte_clear(&init_mm, addr, pte);
+	} else {
+		next = pmd_addr_end(addr, end);
+
+		pmd = pmd_offset(pud, addr);
+		if (pmd_none(*pmd))
+			return next;
+
+		page = pmd_page(*pmd);
+		pmd_clear(pmd);
+	}
+
+	return next;
+}
+
+void __meminit
+vmemmap_kfree(struct page *memmap, unsigned long nr_pages)
+{
+	unsigned long addr = (unsigned long)memmap;
+	unsigned long end = (unsigned long)(memmap + nr_pages);
+	unsigned long next;
+	unsigned int order;
+	struct page *page;
+
+	for (; addr < end; addr = next) {
+		next = find_and_clear_pte_page(addr, end, page);
+		if (!page)
+			continue;
+
+		if (is_vmalloc_addr(page))
+			vfree(page);
+		else {
+			order = next - addr;
+			free_pages((unsigned long)page,
+				   get_order(sizeof(struct page) *  order));
+		}
+	}
+}
+
+void __meminit
+vmemmap_free_bootmem(struct page *memmap, unsigned long nr_pages)
+{
+	unsigned long addr = (unsigned long)memmap;
+	unsigned long end = (unsigned long)(memmap + nr_pages);
+	unsigned long next;
+	struct page *page;
+	unsigned long magic;
+
+	for (; addr < end; addr = next) {
+		next = find_and_clear_pte_page(addr, end, page);
+		if (!page)
+			continue;
+
+		magic = (unsigned long) page->lru.next;
+		if (magic == SECTION_INFO)
+			put_page_bootmem(page);
+	}
+}
+
 void __meminit
 register_page_bootmem_memmap(unsigned long section_nr, struct page *start_page,
 			     unsigned long size)
Index: linux-3.5-rc4/mm/memory_hotplug.c
===================================================================
--- linux-3.5-rc4.orig/mm/memory_hotplug.c	2012-06-27 09:11:13.789150454 +0900
+++ linux-3.5-rc4/mm/memory_hotplug.c	2012-06-27 09:11:16.436117363 +0900
@@ -303,6 +303,8 @@  static int __meminit __add_section(int n
 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 static int __remove_section(struct zone *zone, struct mem_section *ms)
 {
+	unsigned long flags;
+	struct pglist_data *pgdat = zone->zone_pgdat;
 	int ret;

 	if (!valid_section(ms))
@@ -310,6 +312,9 @@  static int __remove_section(struct zone

 	ret = unregister_memory_section(ms);

+	pgdat_resize_lock(pgdat, &flags);
+	sparse_remove_one_section(zone, ms);
+	pgdat_resize_unlock(pgdat, &flags);
 	return ret;
 }
 #else