mm/memory_hotplug: Change pfn_to_section_nr/section_nr_to_pfn macro to inline function
Subsystems (4)
PATCH 1/2 mm/memory_hotplug: Change pfn_to_section_nr/section_nr_to_pfn macro to inline function
pfn_to_section_nr() and section_nr_to_pfn() are defined as macro. pfn_to_section_nr() has no issue even if it is defined as macro. But section_nr_to_pfn() has overflow issue if sec is defined as int.
section_nr_to_pfn() just shifts sec by PFN_SECTION_SHIFT. If sec is defined as unsigned long, section_nr_to_pfn() returns pfn as 64 bit value. But if sec is defined as int, section_nr_to_pfn() returns pfn as 32 bit value.
__remove_section() calculates start_pfn using section_nr_to_pfn() and scn_nr defined as int. So if hot-removed memory address is over 16TB, overflow issue occurs and section_nr_to_pfn() does not calculate correct pfn.
To make callers use proper arg, the patch changes the macros to inline functions.
--- include/linux/mmzone.h | 10 ++++++++-- mm/memory_hotplug.c | 2 +- 2 files changed, 9 insertions(+), 3 deletions(-)
include/linux/mmzone.h +8 -2
@@ -1073,8 +1073,14 @@ static inline unsigned long early_pfn_to_nid(unsigned long pfn)#error Allocator MAX_ORDER exceeds SECTION_SIZE#endif -#define pfn_to_section_nr (pfn) ((pfn) >> PFN_SECTION_SHIFT) -#define section_nr_to_pfn (sec) ((sec) << PFN_SECTION_SHIFT) +static inline unsigned long pfn_to_section_nr (unsigned long pfn) +{ +return pfn >>PFN_SECTION_SHIFT ; +} +static inline unsigned long section_nr_to_pfn (unsigned long sec) +{ +return sec <<PFN_SECTION_SHIFT ; +}#define SECTION_ALIGN_UP (pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)#define SECTION_ALIGN_DOWN (pfn) ((pfn) & PAGE_SECTION_MASK)
mm/memory_hotplug.c +1 -1
@@ -798,7 +798,7 @@ static int __remove_section(struct zone *zone, struct mem_section *ms,return ret; scn_nr =__section_nr (ms); - start_pfn =section_nr_to_pfn (scn_nr); + start_pfn =section_nr_to_pfn ((unsigned long )scn_nr);__remove_zone (zone, start_pfn);sparse_remove_one_section (zone, ms, map_offset);
Signature · 7 lines
1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>
PATCH 2/2 mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long
find_{smallest|biggest}_section_pfn()s find the smallest/biggest section and return the pfn of the section. But the functions are defined as int. So the functions always return 0x00000000 - 0xffffffff. It means if memory address is over 16TB, the functions does not work correctly.
To handle 64 bit value, the patch defines find_{smallest|biggest}_section_pfn() as unsigned long.
--- mm/memory_hotplug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
mm/memory_hotplug.c +2 -2
@@ -582,7 +582,7 @@ int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,#ifdef CONFIG_MEMORY_HOTREMOVE /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ -static int find_smallest_section_pfn (int nid,struct zone *zone, +static unsigned long find_smallest_section_pfn (int nid,struct zone *zone,unsigned long start_pfn,unsigned long end_pfn) {
@@ -607,7 +607,7 @@ static int find_smallest_section_pfn(int nid, struct zone *zone, }/* find the biggest valid pfn in the range [start_pfn, end_pfn). */ -static int find_biggest_section_pfn (int nid,struct zone *zone, +static unsigned long find_biggest_section_pfn (int nid,struct zone *zone,unsigned long start_pfn,unsigned long end_pfn) {
Signature · 7 lines
1.8.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>
Re: [PATCH 2/2] mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long
Quoted 8 lines · YASUAKI ISHIMATSU
find_{smallest|biggest}_section_pfn()s find the smallest/biggest section and return the pfn of the section. But the functions are defined as int. So the functions always return
0x00000000-0xffffffff. It means if memory address is over 16TB, the functions does not work correctly.To handle 64 bit value, the patch defines find_{smallest|biggest}_section_pfn() as unsigned long.
Quoted 1 line
Signed-off-by Yasuaki Ishimatsu <[email protected]>
Quoted 28 lines
--- mm/memory_hotplug.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)mm/memory_hotplug.c +2
-2@@ -582,7 +582,7 @@ int __ref __add_pages(int nid, struct zone *zone, unsigned long phys_start_pfn,#ifdef CONFIG_MEMORY_HOTREMOVE /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ -static int find_smallest_section_pfn (int nid,struct zone *zone, +static unsigned long find_smallest_section_pfn (int nid,struct zone *zone,unsigned long start_pfn,unsigned long end_pfn) {@@ -607,7 +607,7 @@ static int find_smallest_section_pfn(int nid, struct zone *zone, }/* find the biggest valid pfn in the range [start_pfn, end_pfn). */ -static int find_biggest_section_pfn (int nid,struct zone *zone, +static unsigned long find_biggest_section_pfn (int nid,struct zone *zone,unsigned long start_pfn,unsigned long end_pfn) {Signature · 1 line
1.8.3.1
Signature · 8 lines
Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>
Quoted 9 lines · YASUAKI ISHIMATSU
pfn_to_section_nr()andsection_nr_to_pfn()are defined as macro.pfn_to_section_nr()has no issue even if it is defined as macro. Butsection_nr_to_pfn()has overflow issue if sec is defined as int.
section_nr_to_pfn()just shifts sec byPFN_SECTION_SHIFT. If sec is defined as unsigned long,section_nr_to_pfn()returns pfn as 64 bit value. But if sec is defined as int,section_nr_to_pfn()returns pfn as 32 bit value.
Quoted 8 lines
__remove_section()calculatesstart_pfnusingsection_nr_to_pfn()andscn_nrdefined as int. So if hot-removed memory address is over 16TB, overflow issue occurs andsection_nr_to_pfn()does not calculate correct pfn.To make callers use proper arg, the patch changes the macros to inline functions.
I guess the following is due
Quoted 1 line
Signed-off-by Yasuaki Ishimatsu <[email protected]>
Thanks!
Quoted 41 lines
--- include/linux/mmzone.h | 10 ++++++++-- mm/memory_hotplug.c | 2 +- 2 files changed, 9 insertions(+), 3 deletions(-)include/linux/mmzone.h +8
-2@@ -1073,8 +1073,14 @@ static inline unsigned long early_pfn_to_nid(unsigned long pfn)#error Allocator MAX_ORDER exceeds SECTION_SIZE#endif -#define pfn_to_section_nr (pfn) ((pfn) >> PFN_SECTION_SHIFT) -#define section_nr_to_pfn (sec) ((sec) << PFN_SECTION_SHIFT) +static inline unsigned long pfn_to_section_nr (unsigned long pfn) +{ +return pfn >>PFN_SECTION_SHIFT ; +} +static inline unsigned long section_nr_to_pfn (unsigned long sec) +{ +return sec <<PFN_SECTION_SHIFT ; +}#define SECTION_ALIGN_UP (pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)#define SECTION_ALIGN_DOWN (pfn) ((pfn) & PAGE_SECTION_MASK)mm/memory_hotplug.c +1
-1@@ -798,7 +798,7 @@ static int __remove_section(struct zone *zone, struct mem_section *ms,return ret; scn_nr =__section_nr (ms); - start_pfn =section_nr_to_pfn (scn_nr); + start_pfn =section_nr_to_pfn ((unsigned long )scn_nr);__remove_zone (zone, start_pfn);sparse_remove_one_section (zone, ms, map_offset);Signature · 1 line
1.8.3.1
Signature · 8 lines
Michal Hocko SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>