Re: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
On Wed, Sep 16, 2020 at 08:34:10PM +0200, David Hildenbrand wrote: > Page isolation doesn't actually touch the pages, it simply isolates > pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist. > > We already place pages to the tail of the freelists when undoing > isolation via __putback_isolated_page(), let's do it in any case > (e.g., if order == pageblock_order) and document the behavior. > > This change results in all pages getting onlined via online_pages() to > be placed to the tail of the freelist. > > Cc: Andrew Morton > Cc: Alexander Duyck > Cc: Mel Gorman > Cc: Michal Hocko > Cc: Dave Hansen > Cc: Vlastimil Babka > Cc: Wei Yang > Cc: Oscar Salvador > Cc: Mike Rapoport > Cc: Scott Cheloha > Cc: Michael Ellerman > Signed-off-by: David Hildenbrand LGTM. Feel the same way about move_freepages_block_tail/move_freepages_block_tail wrappers, I think we are better off without them. Reviewed-by: Oscar Salvador Thanks -- Oscar Salvador SUSE L3
Re: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
On 9/25/20 10:05 AM, David Hildenbrand wrote:
static inline void del_page_from_free_list(struct page *page, struct zone
*zone,
unsigned int order)
{
@@ -2323,7 +2332,7 @@ static inline struct page
*__rmqueue_cma_fallback(struct zone *zone,
*/
static int move_freepages(struct zone *zone,
struct page *start_page, struct page *end_page,
-int migratetype, int *num_movable)
+int migratetype, int *num_movable, bool to_tail)
{
struct page *page;
unsigned int order;
@@ -2354,7 +2363,10 @@ static int move_freepages(struct zone *zone,
VM_BUG_ON_PAGE(page_zone(page) != zone, page);
order = page_order(page);
- move_to_free_list(page, zone, order, migratetype);
+ if (to_tail)
+ move_to_free_list_tail(page, zone, order, migratetype);
+ else
+ move_to_free_list(page, zone, order, migratetype);
page += 1 << order;
pages_moved += 1 << order;
}
@@ -2362,8 +2374,9 @@ static int move_freepages(struct zone *zone,
return pages_moved;
}
-int move_freepages_block(struct zone *zone, struct page *page,
- int migratetype, int *num_movable)
+static int __move_freepages_block(struct zone *zone, struct page *page,
+int migratetype, int *num_movable,
+bool to_tail)
{
unsigned long start_pfn, end_pfn;
struct page *start_page, *end_page;
@@ -2384,7 +2397,20 @@ int move_freepages_block(struct zone *zone, struct
page *page,
return 0;
return move_freepages(zone, start_page, end_page, migratetype,
- num_movable);
+num_movable, to_tail);
+}
+
+int move_freepages_block(struct zone *zone, struct page *page,
+ int migratetype, int *num_movable)
+{
+ return __move_freepages_block(zone, page, migratetype, num_movable,
+false);
+}
+
+int move_freepages_block_tail(struct zone *zone, struct page *page,
+int migratetype)
+{
+ return __move_freepages_block(zone, page, migratetype, NULL, true);
}
>>>
>>> Likewise, just 5 callers of move_freepages_block(), all in the files you're
>>> already changing, so no need for this wrappers IMHO.
>
> As long as we don't want to move the implementation to the header, we'll
> need it for the constant propagation to work at compile time (we don't
> really have link-time optimizations). Or am I missing something?
I guess move_freepages_block() is not exactly fast path, so we could do without
it.
> Thanks!
>
Re: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
On 25.09.20 04:45, Wei Yang wrote:
> On Thu, Sep 24, 2020 at 01:13:29PM +0200, Vlastimil Babka wrote:
>> On 9/16/20 8:34 PM, David Hildenbrand wrote:
>>> Page isolation doesn't actually touch the pages, it simply isolates
>>> pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist.
>>>
>>> We already place pages to the tail of the freelists when undoing
>>> isolation via __putback_isolated_page(), let's do it in any case
>>> (e.g., if order == pageblock_order) and document the behavior.
>>>
>>> This change results in all pages getting onlined via online_pages() to
>>> be placed to the tail of the freelist.
>>>
>>> Cc: Andrew Morton
>>> Cc: Alexander Duyck
>>> Cc: Mel Gorman
>>> Cc: Michal Hocko
>>> Cc: Dave Hansen
>>> Cc: Vlastimil Babka
>>> Cc: Wei Yang
>>> Cc: Oscar Salvador
>>> Cc: Mike Rapoport
>>> Cc: Scott Cheloha
>>> Cc: Michael Ellerman
>>> Signed-off-by: David Hildenbrand
>>> ---
>>> include/linux/page-isolation.h | 2 ++
>>> mm/page_alloc.c| 36 +-
>>> mm/page_isolation.c| 8 ++--
>>> 3 files changed, 39 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
>>> index 572458016331..a36be2cf4dbb 100644
>>> --- a/include/linux/page-isolation.h
>>> +++ b/include/linux/page-isolation.h
>>> @@ -38,6 +38,8 @@ struct page *has_unmovable_pages(struct zone *zone,
>>> struct page *page,
>>> void set_pageblock_migratetype(struct page *page, int migratetype);
>>> int move_freepages_block(struct zone *zone, struct page *page,
>>> int migratetype, int *num_movable);
>>> +int move_freepages_block_tail(struct zone *zone, struct page *page,
>>> + int migratetype);
>>>
>>> /*
>>> * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
>>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>>> index bba9a0f60c70..75b0f49b4022 100644
>>> --- a/mm/page_alloc.c
>>> +++ b/mm/page_alloc.c
>>> @@ -899,6 +899,15 @@ static inline void move_to_free_list(struct page
>>> *page, struct zone *zone,
>>> list_move(&page->lru, &area->free_list[migratetype]);
>>> }
>>>
>>> +/* Used for pages which are on another list */
>>> +static inline void move_to_free_list_tail(struct page *page, struct zone
>>> *zone,
>>> + unsigned int order, int migratetype)
>>> +{
>>> + struct free_area *area = &zone->free_area[order];
>>> +
>>> + list_move_tail(&page->lru, &area->free_list[migratetype]);
>>> +}
>>
>> There are just 3 callers of move_to_free_list() before this patch, I would
>> just
>> add the to_tail parameter there instead of new wrapper. For callers with
>> constant parameter, the inline will eliminate it anyway.
>
> Got the same feeling :-)
I once was told boolean parameters are the root of all evil, so I tried
to keep them file-local :)
One thing to be aware of is, that inline optimizations won't help as
long as this function is in mm/page_alloc.c, see below.
>
>>
>>> static inline void del_page_from_free_list(struct page *page, struct zone
>>> *zone,
>>>unsigned int order)
>>> {
>>> @@ -2323,7 +2332,7 @@ static inline struct page
>>> *__rmqueue_cma_fallback(struct zone *zone,
>>> */
>>> static int move_freepages(struct zone *zone,
>>> struct page *start_page, struct page *end_page,
>>> - int migratetype, int *num_movable)
>>> + int migratetype, int *num_movable, bool to_tail)
>>> {
>>> struct page *page;
>>> unsigned int order;
>>> @@ -2354,7 +2363,10 @@ static int move_freepages(struct zone *zone,
>>> VM_BUG_ON_PAGE(page_zone(page) != zone, page);
>>>
>>> order = page_order(page);
>>> - move_to_free_list(page, zone, order, migratetype);
>>> + if (to_tail)
>>> + move_to_free_list_tail(page, zone, order, migratetype);
>>> + else
>>> + move_to_free_list(page, zone, order, migratetype);
>>> page += 1 << order;
>>> pages_moved += 1 << order;
>>> }
>>> @@ -2362,8 +2374,9 @@ static int move_freepages(struct zone *zone,
>>> return pages_moved;
>>> }
>>>
>>> -int move_freepages_block(struct zone *zone, struct page *page,
>>> - int migratetype, int *num_movable)
>>> +static int __move_freepages_block(struct zone *zone, struct page *page,
>>> + int migratetype, int *num_movable,
>>> + bool to_tail)
>>> {
>>> unsigned long start_pfn, end_pfn;
>>> struct page *start_page, *end_page;
>>> @@ -2384,7 +2397,20 @@ int move_freepages_block(struct zone *zone, struct
>>> page *page,
>>> return 0;
>>>
>>> return move_freepages(zone, start_page, end_page, migratetype,
>>> - num_m
Re: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
On Thu, Sep 24, 2020 at 01:13:29PM +0200, Vlastimil Babka wrote:
>On 9/16/20 8:34 PM, David Hildenbrand wrote:
>> Page isolation doesn't actually touch the pages, it simply isolates
>> pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist.
>>
>> We already place pages to the tail of the freelists when undoing
>> isolation via __putback_isolated_page(), let's do it in any case
>> (e.g., if order == pageblock_order) and document the behavior.
>>
>> This change results in all pages getting onlined via online_pages() to
>> be placed to the tail of the freelist.
>>
>> Cc: Andrew Morton
>> Cc: Alexander Duyck
>> Cc: Mel Gorman
>> Cc: Michal Hocko
>> Cc: Dave Hansen
>> Cc: Vlastimil Babka
>> Cc: Wei Yang
>> Cc: Oscar Salvador
>> Cc: Mike Rapoport
>> Cc: Scott Cheloha
>> Cc: Michael Ellerman
>> Signed-off-by: David Hildenbrand
>> ---
>> include/linux/page-isolation.h | 2 ++
>> mm/page_alloc.c| 36 +-
>> mm/page_isolation.c| 8 ++--
>> 3 files changed, 39 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
>> index 572458016331..a36be2cf4dbb 100644
>> --- a/include/linux/page-isolation.h
>> +++ b/include/linux/page-isolation.h
>> @@ -38,6 +38,8 @@ struct page *has_unmovable_pages(struct zone *zone, struct
>> page *page,
>> void set_pageblock_migratetype(struct page *page, int migratetype);
>> int move_freepages_block(struct zone *zone, struct page *page,
>> int migratetype, int *num_movable);
>> +int move_freepages_block_tail(struct zone *zone, struct page *page,
>> + int migratetype);
>>
>> /*
>> * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index bba9a0f60c70..75b0f49b4022 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -899,6 +899,15 @@ static inline void move_to_free_list(struct page *page,
>> struct zone *zone,
>> list_move(&page->lru, &area->free_list[migratetype]);
>> }
>>
>> +/* Used for pages which are on another list */
>> +static inline void move_to_free_list_tail(struct page *page, struct zone
>> *zone,
>> + unsigned int order, int migratetype)
>> +{
>> +struct free_area *area = &zone->free_area[order];
>> +
>> +list_move_tail(&page->lru, &area->free_list[migratetype]);
>> +}
>
>There are just 3 callers of move_to_free_list() before this patch, I would just
>add the to_tail parameter there instead of new wrapper. For callers with
>constant parameter, the inline will eliminate it anyway.
Got the same feeling :-)
>
>> static inline void del_page_from_free_list(struct page *page, struct zone
>> *zone,
>> unsigned int order)
>> {
>> @@ -2323,7 +2332,7 @@ static inline struct page
>> *__rmqueue_cma_fallback(struct zone *zone,
>> */
>> static int move_freepages(struct zone *zone,
>>struct page *start_page, struct page *end_page,
>> - int migratetype, int *num_movable)
>> + int migratetype, int *num_movable, bool to_tail)
>> {
>> struct page *page;
>> unsigned int order;
>> @@ -2354,7 +2363,10 @@ static int move_freepages(struct zone *zone,
>> VM_BUG_ON_PAGE(page_zone(page) != zone, page);
>>
>> order = page_order(page);
>> -move_to_free_list(page, zone, order, migratetype);
>> +if (to_tail)
>> +move_to_free_list_tail(page, zone, order, migratetype);
>> +else
>> +move_to_free_list(page, zone, order, migratetype);
>> page += 1 << order;
>> pages_moved += 1 << order;
>> }
>> @@ -2362,8 +2374,9 @@ static int move_freepages(struct zone *zone,
>> return pages_moved;
>> }
>>
>> -int move_freepages_block(struct zone *zone, struct page *page,
>> -int migratetype, int *num_movable)
>> +static int __move_freepages_block(struct zone *zone, struct page *page,
>> + int migratetype, int *num_movable,
>> + bool to_tail)
>> {
>> unsigned long start_pfn, end_pfn;
>> struct page *start_page, *end_page;
>> @@ -2384,7 +2397,20 @@ int move_freepages_block(struct zone *zone, struct
>> page *page,
>> return 0;
>>
>> return move_freepages(zone, start_page, end_page, migratetype,
>> -num_movable);
>> + num_movable, to_tail);
>> +}
>> +
>> +int move_freepages_block(struct zone *zone, struct page *page,
>> + int migratetype, int *num_movable)
>> +{
>> +return __move_freepages_block(zone, page, migratetype, num_movable,
>> + false);
>> +}
>> +
>> +int move_f
Re: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
On 9/16/20 8:34 PM, David Hildenbrand wrote:
> Page isolation doesn't actually touch the pages, it simply isolates
> pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist.
>
> We already place pages to the tail of the freelists when undoing
> isolation via __putback_isolated_page(), let's do it in any case
> (e.g., if order == pageblock_order) and document the behavior.
>
> This change results in all pages getting onlined via online_pages() to
> be placed to the tail of the freelist.
>
> Cc: Andrew Morton
> Cc: Alexander Duyck
> Cc: Mel Gorman
> Cc: Michal Hocko
> Cc: Dave Hansen
> Cc: Vlastimil Babka
> Cc: Wei Yang
> Cc: Oscar Salvador
> Cc: Mike Rapoport
> Cc: Scott Cheloha
> Cc: Michael Ellerman
> Signed-off-by: David Hildenbrand
> ---
> include/linux/page-isolation.h | 2 ++
> mm/page_alloc.c| 36 +-
> mm/page_isolation.c| 8 ++--
> 3 files changed, 39 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
> index 572458016331..a36be2cf4dbb 100644
> --- a/include/linux/page-isolation.h
> +++ b/include/linux/page-isolation.h
> @@ -38,6 +38,8 @@ struct page *has_unmovable_pages(struct zone *zone, struct
> page *page,
> void set_pageblock_migratetype(struct page *page, int migratetype);
> int move_freepages_block(struct zone *zone, struct page *page,
> int migratetype, int *num_movable);
> +int move_freepages_block_tail(struct zone *zone, struct page *page,
> + int migratetype);
>
> /*
> * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index bba9a0f60c70..75b0f49b4022 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -899,6 +899,15 @@ static inline void move_to_free_list(struct page *page,
> struct zone *zone,
> list_move(&page->lru, &area->free_list[migratetype]);
> }
>
> +/* Used for pages which are on another list */
> +static inline void move_to_free_list_tail(struct page *page, struct zone
> *zone,
> + unsigned int order, int migratetype)
> +{
> + struct free_area *area = &zone->free_area[order];
> +
> + list_move_tail(&page->lru, &area->free_list[migratetype]);
> +}
There are just 3 callers of move_to_free_list() before this patch, I would just
add the to_tail parameter there instead of new wrapper. For callers with
constant parameter, the inline will eliminate it anyway.
> static inline void del_page_from_free_list(struct page *page, struct zone
> *zone,
> unsigned int order)
> {
> @@ -2323,7 +2332,7 @@ static inline struct page
> *__rmqueue_cma_fallback(struct zone *zone,
> */
> static int move_freepages(struct zone *zone,
> struct page *start_page, struct page *end_page,
> - int migratetype, int *num_movable)
> + int migratetype, int *num_movable, bool to_tail)
> {
> struct page *page;
> unsigned int order;
> @@ -2354,7 +2363,10 @@ static int move_freepages(struct zone *zone,
> VM_BUG_ON_PAGE(page_zone(page) != zone, page);
>
> order = page_order(page);
> - move_to_free_list(page, zone, order, migratetype);
> + if (to_tail)
> + move_to_free_list_tail(page, zone, order, migratetype);
> + else
> + move_to_free_list(page, zone, order, migratetype);
> page += 1 << order;
> pages_moved += 1 << order;
> }
> @@ -2362,8 +2374,9 @@ static int move_freepages(struct zone *zone,
> return pages_moved;
> }
>
> -int move_freepages_block(struct zone *zone, struct page *page,
> - int migratetype, int *num_movable)
> +static int __move_freepages_block(struct zone *zone, struct page *page,
> + int migratetype, int *num_movable,
> + bool to_tail)
> {
> unsigned long start_pfn, end_pfn;
> struct page *start_page, *end_page;
> @@ -2384,7 +2397,20 @@ int move_freepages_block(struct zone *zone, struct
> page *page,
> return 0;
>
> return move_freepages(zone, start_page, end_page, migratetype,
> - num_movable);
> + num_movable, to_tail);
> +}
> +
> +int move_freepages_block(struct zone *zone, struct page *page,
> + int migratetype, int *num_movable)
> +{
> + return __move_freepages_block(zone, page, migratetype, num_movable,
> + false);
> +}
> +
> +int move_freepages_block_tail(struct zone *zone, struct page *page,
> + int migratetype)
> +{
> + return __move_freepages_block(zone, page, migratetype, NULL,
Re: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
On 18.09.20 04:29, Wei Yang wrote: > On Wed, Sep 16, 2020 at 08:34:10PM +0200, David Hildenbrand wrote: >> Page isolation doesn't actually touch the pages, it simply isolates >> pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist. >> >> We already place pages to the tail of the freelists when undoing >> isolation via __putback_isolated_page(), let's do it in any case >> (e.g., if order == pageblock_order) and document the behavior. >> >> This change results in all pages getting onlined via online_pages() to >> be placed to the tail of the freelist. > > I am sorry to not follow again. unset_migratetype_isolate() is used in > __offline_pages if my understanding is correct. How does it contribute on > online_pages? See -next / -mm, that should make it clearer. -- Thanks, David / dhildenb
Re: [PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
On Wed, Sep 16, 2020 at 08:34:10PM +0200, David Hildenbrand wrote:
>Page isolation doesn't actually touch the pages, it simply isolates
>pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist.
>
>We already place pages to the tail of the freelists when undoing
>isolation via __putback_isolated_page(), let's do it in any case
>(e.g., if order == pageblock_order) and document the behavior.
>
>This change results in all pages getting onlined via online_pages() to
>be placed to the tail of the freelist.
I am sorry to not follow again. unset_migratetype_isolate() is used in
__offline_pages if my understanding is correct. How does it contribute on
online_pages?
>
>Cc: Andrew Morton
>Cc: Alexander Duyck
>Cc: Mel Gorman
>Cc: Michal Hocko
>Cc: Dave Hansen
>Cc: Vlastimil Babka
>Cc: Wei Yang
>Cc: Oscar Salvador
>Cc: Mike Rapoport
>Cc: Scott Cheloha
>Cc: Michael Ellerman
>Signed-off-by: David Hildenbrand
>---
> include/linux/page-isolation.h | 2 ++
> mm/page_alloc.c| 36 +-
> mm/page_isolation.c| 8 ++--
> 3 files changed, 39 insertions(+), 7 deletions(-)
>
>diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
>index 572458016331..a36be2cf4dbb 100644
>--- a/include/linux/page-isolation.h
>+++ b/include/linux/page-isolation.h
>@@ -38,6 +38,8 @@ struct page *has_unmovable_pages(struct zone *zone, struct
>page *page,
> void set_pageblock_migratetype(struct page *page, int migratetype);
> int move_freepages_block(struct zone *zone, struct page *page,
> int migratetype, int *num_movable);
>+int move_freepages_block_tail(struct zone *zone, struct page *page,
>+int migratetype);
>
> /*
> * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
>diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>index bba9a0f60c70..75b0f49b4022 100644
>--- a/mm/page_alloc.c
>+++ b/mm/page_alloc.c
>@@ -899,6 +899,15 @@ static inline void move_to_free_list(struct page *page,
>struct zone *zone,
> list_move(&page->lru, &area->free_list[migratetype]);
> }
>
>+/* Used for pages which are on another list */
>+static inline void move_to_free_list_tail(struct page *page, struct zone
>*zone,
>+unsigned int order, int migratetype)
>+{
>+ struct free_area *area = &zone->free_area[order];
>+
>+ list_move_tail(&page->lru, &area->free_list[migratetype]);
>+}
>+
> static inline void del_page_from_free_list(struct page *page, struct zone
> *zone,
> unsigned int order)
> {
>@@ -2323,7 +2332,7 @@ static inline struct page *__rmqueue_cma_fallback(struct
>zone *zone,
> */
> static int move_freepages(struct zone *zone,
> struct page *start_page, struct page *end_page,
>-int migratetype, int *num_movable)
>+int migratetype, int *num_movable, bool to_tail)
> {
> struct page *page;
> unsigned int order;
>@@ -2354,7 +2363,10 @@ static int move_freepages(struct zone *zone,
> VM_BUG_ON_PAGE(page_zone(page) != zone, page);
>
> order = page_order(page);
>- move_to_free_list(page, zone, order, migratetype);
>+ if (to_tail)
>+ move_to_free_list_tail(page, zone, order, migratetype);
>+ else
>+ move_to_free_list(page, zone, order, migratetype);
> page += 1 << order;
> pages_moved += 1 << order;
> }
>@@ -2362,8 +2374,9 @@ static int move_freepages(struct zone *zone,
> return pages_moved;
> }
>
>-int move_freepages_block(struct zone *zone, struct page *page,
>- int migratetype, int *num_movable)
>+static int __move_freepages_block(struct zone *zone, struct page *page,
>+int migratetype, int *num_movable,
>+bool to_tail)
> {
> unsigned long start_pfn, end_pfn;
> struct page *start_page, *end_page;
>@@ -2384,7 +2397,20 @@ int move_freepages_block(struct zone *zone, struct page
>*page,
> return 0;
>
> return move_freepages(zone, start_page, end_page, migratetype,
>- num_movable);
>+num_movable, to_tail);
>+}
>+
>+int move_freepages_block(struct zone *zone, struct page *page,
>+ int migratetype, int *num_movable)
>+{
>+ return __move_freepages_block(zone, page, migratetype, num_movable,
>+false);
>+}
>+
>+int move_freepages_block_tail(struct zone *zone, struct page *page,
>+int migratetype)
>+{
>+ return __move_freepages_block(zone, page, migratetype, NULL, true);
> }
>
> static void change_pageblock_range(struct page *pageblock_page,
>diff --git a/mm/page_is
[PATCH RFC 3/4] mm/page_alloc: always move pages to the tail of the freelist in unset_migratetype_isolate()
Page isolation doesn't actually touch the pages, it simply isolates
pageblocks and moves all free pages to the MIGRATE_ISOLATE freelist.
We already place pages to the tail of the freelists when undoing
isolation via __putback_isolated_page(), let's do it in any case
(e.g., if order == pageblock_order) and document the behavior.
This change results in all pages getting onlined via online_pages() to
be placed to the tail of the freelist.
Cc: Andrew Morton
Cc: Alexander Duyck
Cc: Mel Gorman
Cc: Michal Hocko
Cc: Dave Hansen
Cc: Vlastimil Babka
Cc: Wei Yang
Cc: Oscar Salvador
Cc: Mike Rapoport
Cc: Scott Cheloha
Cc: Michael Ellerman
Signed-off-by: David Hildenbrand
---
include/linux/page-isolation.h | 2 ++
mm/page_alloc.c| 36 +-
mm/page_isolation.c| 8 ++--
3 files changed, 39 insertions(+), 7 deletions(-)
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
index 572458016331..a36be2cf4dbb 100644
--- a/include/linux/page-isolation.h
+++ b/include/linux/page-isolation.h
@@ -38,6 +38,8 @@ struct page *has_unmovable_pages(struct zone *zone, struct
page *page,
void set_pageblock_migratetype(struct page *page, int migratetype);
int move_freepages_block(struct zone *zone, struct page *page,
int migratetype, int *num_movable);
+int move_freepages_block_tail(struct zone *zone, struct page *page,
+ int migratetype);
/*
* Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bba9a0f60c70..75b0f49b4022 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -899,6 +899,15 @@ static inline void move_to_free_list(struct page *page,
struct zone *zone,
list_move(&page->lru, &area->free_list[migratetype]);
}
+/* Used for pages which are on another list */
+static inline void move_to_free_list_tail(struct page *page, struct zone *zone,
+ unsigned int order, int migratetype)
+{
+ struct free_area *area = &zone->free_area[order];
+
+ list_move_tail(&page->lru, &area->free_list[migratetype]);
+}
+
static inline void del_page_from_free_list(struct page *page, struct zone
*zone,
unsigned int order)
{
@@ -2323,7 +2332,7 @@ static inline struct page *__rmqueue_cma_fallback(struct
zone *zone,
*/
static int move_freepages(struct zone *zone,
struct page *start_page, struct page *end_page,
- int migratetype, int *num_movable)
+ int migratetype, int *num_movable, bool to_tail)
{
struct page *page;
unsigned int order;
@@ -2354,7 +2363,10 @@ static int move_freepages(struct zone *zone,
VM_BUG_ON_PAGE(page_zone(page) != zone, page);
order = page_order(page);
- move_to_free_list(page, zone, order, migratetype);
+ if (to_tail)
+ move_to_free_list_tail(page, zone, order, migratetype);
+ else
+ move_to_free_list(page, zone, order, migratetype);
page += 1 << order;
pages_moved += 1 << order;
}
@@ -2362,8 +2374,9 @@ static int move_freepages(struct zone *zone,
return pages_moved;
}
-int move_freepages_block(struct zone *zone, struct page *page,
- int migratetype, int *num_movable)
+static int __move_freepages_block(struct zone *zone, struct page *page,
+ int migratetype, int *num_movable,
+ bool to_tail)
{
unsigned long start_pfn, end_pfn;
struct page *start_page, *end_page;
@@ -2384,7 +2397,20 @@ int move_freepages_block(struct zone *zone, struct page
*page,
return 0;
return move_freepages(zone, start_page, end_page, migratetype,
- num_movable);
+ num_movable, to_tail);
+}
+
+int move_freepages_block(struct zone *zone, struct page *page,
+int migratetype, int *num_movable)
+{
+ return __move_freepages_block(zone, page, migratetype, num_movable,
+ false);
+}
+
+int move_freepages_block_tail(struct zone *zone, struct page *page,
+ int migratetype)
+{
+ return __move_freepages_block(zone, page, migratetype, NULL, true);
}
static void change_pageblock_range(struct page *pageblock_page,
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index abfe26ad59fd..84aa1d14751d 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -83,7 +83,7 @@ static void unset_migratetype_isolate(struct page *page,
unsigned migratetype)
* Because freepage with more than pageblock_order on isolated
* pageblock is
