[v5,2/3] mm/compaction: add support for >0 order folio memory compaction.
Commit Message
From: Zi Yan <ziy@nvidia.com>
Before last commit, memory compaction only migrates order-0 folios and
skips >0 order folios. Last commit splits all >0 order folios during
compaction. This commit migrates >0 order folios during compaction by
keeping isolated free pages at their original size without splitting them
into order-0 pages and using them directly during migration process.
What is different from the prior implementation:
1. All isolated free pages are kept in a NR_PAGE_ORDERS array of page
lists, where each page list stores free pages in the same order.
2. All free pages are not post_alloc_hook() processed nor buddy pages,
although their orders are stored in first page's private like buddy
pages.
3. During migration, in new page allocation time (i.e., in
compaction_alloc()), free pages are then processed by post_alloc_hook().
When migration fails and a new page is returned (i.e., in
compaction_free()), free pages are restored by reversing the
post_alloc_hook() operations using newly added
free_pages_prepare_fpi_none().
Step 3 is done for a latter optimization that splitting and/or merging
free pages during compaction becomes easier.
Note: without splitting free pages, compaction can end prematurely due to
migration will return -ENOMEM even if there is free pages. This happens
when no order-0 free page exist and compaction_alloc() return NULL.
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Adam Manzanares <a.manzanares@samsung.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yin Fengwei <fengwei.yin@intel.com>
---
mm/compaction.c | 143 +++++++++++++++++++++++++++---------------------
mm/internal.h | 4 +-
mm/page_alloc.c | 6 ++
3 files changed, 91 insertions(+), 62 deletions(-)
Comments
On 2/14/24 23:04, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
>
> Before last commit, memory compaction only migrates order-0 folios and
> skips >0 order folios. Last commit splits all >0 order folios during
> compaction. This commit migrates >0 order folios during compaction by
> keeping isolated free pages at their original size without splitting them
> into order-0 pages and using them directly during migration process.
>
> What is different from the prior implementation:
> 1. All isolated free pages are kept in a NR_PAGE_ORDERS array of page
> lists, where each page list stores free pages in the same order.
> 2. All free pages are not post_alloc_hook() processed nor buddy pages,
> although their orders are stored in first page's private like buddy
> pages.
> 3. During migration, in new page allocation time (i.e., in
> compaction_alloc()), free pages are then processed by post_alloc_hook().
> When migration fails and a new page is returned (i.e., in
> compaction_free()), free pages are restored by reversing the
> post_alloc_hook() operations using newly added
> free_pages_prepare_fpi_none().
>
> Step 3 is done for a latter optimization that splitting and/or merging
> free pages during compaction becomes easier.
>
> Note: without splitting free pages, compaction can end prematurely due to
> migration will return -ENOMEM even if there is free pages. This happens
> when no order-0 free page exist and compaction_alloc() return NULL.
>
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> Tested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Noticed a possible simplification:
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -447,6 +447,8 @@ extern void prep_compound_page(struct page *page, unsigned int order);
>
> extern void post_alloc_hook(struct page *page, unsigned int order,
> gfp_t gfp_flags);
> +extern bool free_pages_prepare_fpi_none(struct page *page, unsigned int order);
> +
> extern int user_min_free_kbytes;
>
> extern void free_unref_page(struct page *page, unsigned int order);
> @@ -481,7 +483,7 @@ int split_free_page(struct page *free_page,
> * completes when free_pfn <= migrate_pfn
> */
> struct compact_control {
> - struct list_head freepages; /* List of free pages to migrate to */
> + struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */
> struct list_head migratepages; /* List of pages being migrated */
> unsigned int nr_freepages; /* Number of isolated free pages */
> unsigned int nr_migratepages; /* Number of pages to migrate */
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 7ae4b74c9e5c..e6e2ac722a82 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -1179,6 +1179,12 @@ static __always_inline bool free_pages_prepare(struct page *page,
> return true;
> }
>
> +__always_inline bool free_pages_prepare_fpi_none(struct page *page,
> + unsigned int order)
> +{
> + return free_pages_prepare(page, order, FPI_NONE);
Seems like free_pages_prepare() currently only passes fpi_flags to
should_skip_kasan_poison() and that ignores them. You could remove the
parameter from both and declare and use free_pages_prepare(page, order)
directly.
> +}
> +
> /*
> * Frees a number of pages from the PCP lists
> * Assumes all pages on list are in same zone.
On 15 Feb 2024, at 11:07, Vlastimil Babka wrote:
> On 2/14/24 23:04, Zi Yan wrote:
>> From: Zi Yan <ziy@nvidia.com>
>>
>> Before last commit, memory compaction only migrates order-0 folios and
>> skips >0 order folios. Last commit splits all >0 order folios during
>> compaction. This commit migrates >0 order folios during compaction by
>> keeping isolated free pages at their original size without splitting them
>> into order-0 pages and using them directly during migration process.
>>
>> What is different from the prior implementation:
>> 1. All isolated free pages are kept in a NR_PAGE_ORDERS array of page
>> lists, where each page list stores free pages in the same order.
>> 2. All free pages are not post_alloc_hook() processed nor buddy pages,
>> although their orders are stored in first page's private like buddy
>> pages.
>> 3. During migration, in new page allocation time (i.e., in
>> compaction_alloc()), free pages are then processed by post_alloc_hook().
>> When migration fails and a new page is returned (i.e., in
>> compaction_free()), free pages are restored by reversing the
>> post_alloc_hook() operations using newly added
>> free_pages_prepare_fpi_none().
>>
>> Step 3 is done for a latter optimization that splitting and/or merging
>> free pages during compaction becomes easier.
>>
>> Note: without splitting free pages, compaction can end prematurely due to
>> migration will return -ENOMEM even if there is free pages. This happens
>> when no order-0 free page exist and compaction_alloc() return NULL.
>>
>> Signed-off-by: Zi Yan <ziy@nvidia.com>
>> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com>
>> Tested-by: Yu Zhao <yuzhao@google.com>
>
> Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Thanks.
>
> Noticed a possible simplification:
>
>> --- a/mm/internal.h
>> +++ b/mm/internal.h
>> @@ -447,6 +447,8 @@ extern void prep_compound_page(struct page *page, unsigned int order);
>>
>> extern void post_alloc_hook(struct page *page, unsigned int order,
>> gfp_t gfp_flags);
>> +extern bool free_pages_prepare_fpi_none(struct page *page, unsigned int order);
>> +
>> extern int user_min_free_kbytes;
>>
>> extern void free_unref_page(struct page *page, unsigned int order);
>> @@ -481,7 +483,7 @@ int split_free_page(struct page *free_page,
>> * completes when free_pfn <= migrate_pfn
>> */
>> struct compact_control {
>> - struct list_head freepages; /* List of free pages to migrate to */
>> + struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */
>> struct list_head migratepages; /* List of pages being migrated */
>> unsigned int nr_freepages; /* Number of isolated free pages */
>> unsigned int nr_migratepages; /* Number of pages to migrate */
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 7ae4b74c9e5c..e6e2ac722a82 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -1179,6 +1179,12 @@ static __always_inline bool free_pages_prepare(struct page *page,
>> return true;
>> }
>>
>> +__always_inline bool free_pages_prepare_fpi_none(struct page *page,
>> + unsigned int order)
>> +{
>> + return free_pages_prepare(page, order, FPI_NONE);
>
> Seems like free_pages_prepare() currently only passes fpi_flags to
> should_skip_kasan_poison() and that ignores them. You could remove the
> parameter from both and declare and use free_pages_prepare(page, order)
> directly.
Got it. I can send a cleanup patch after this series. No, to avoid unnecessary
code churn, it is better to put a cleanup patch before this series and use
free_pages_prepare(). Will do it in v6.
>> +}
>> +
>> /*
>> * Frees a number of pages from the PCP lists
>> * Assumes all pages on list are in same zone.
--
Best Regards,
Yan, Zi
On 2/14/24 23:04, Zi Yan wrote:
> @@ -1849,10 +1857,22 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data)
> static void compaction_free(struct folio *dst, unsigned long data)
> {
> struct compact_control *cc = (struct compact_control *)data;
> + int order = folio_order(dst);
> + struct page *page = &dst->page;
> +
> + if (folio_put_testzero(dst)) {
> + free_pages_prepare_fpi_none(page, order);
> +
> + INIT_LIST_HEAD(&dst->lru);
(is this even needed? I think the state of first parameter of list_add() is
never expected to be in particular state?)
>
> - list_add(&dst->lru, &cc->freepages);
> - cc->nr_freepages++;
> - cc->nr_migratepages += 1 << folio_order(dst);
> + list_add(&dst->lru, &cc->freepages[order]);
> + cc->nr_freepages += 1 << order;
> + cc->nr_migratepages += 1 << order;
Hm actually this increment of nr_migratepages should happen even if we lost
the free page.
> + }
> + /*
> + * someone else has referenced the page, we cannot take it back to our
> + * free list.
> + */
> }
On 15 Feb 2024, at 11:57, Vlastimil Babka wrote:
> On 2/14/24 23:04, Zi Yan wrote:
>> @@ -1849,10 +1857,22 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data)
>> static void compaction_free(struct folio *dst, unsigned long data)
>> {
>> struct compact_control *cc = (struct compact_control *)data;
>> + int order = folio_order(dst);
>> + struct page *page = &dst->page;
>> +
>> + if (folio_put_testzero(dst)) {
>> + free_pages_prepare_fpi_none(page, order);
>> +
>> + INIT_LIST_HEAD(&dst->lru);
>
> (is this even needed? I think the state of first parameter of list_add() is
> never expected to be in particular state?)
There is a __list_add_valid() performing list corruption checks.
>
>>
>> - list_add(&dst->lru, &cc->freepages);
>> - cc->nr_freepages++;
>> - cc->nr_migratepages += 1 << folio_order(dst);
>> + list_add(&dst->lru, &cc->freepages[order]);
>> + cc->nr_freepages += 1 << order;
>> + cc->nr_migratepages += 1 << order;
>
> Hm actually this increment of nr_migratepages should happen even if we lost
> the free page.
Because compaction_free() indicates the page is not migrated and nr_migratepages
should be increased regardless.
Will fix it. Thanks.
>> + }
>> + /*
>> + * someone else has referenced the page, we cannot take it back to our
>> + * free list.
>> + */
>> }
--
Best Regards,
Yan, Zi
On 2/15/24 18:32, Zi Yan wrote:
> On 15 Feb 2024, at 11:57, Vlastimil Babka wrote:
>
>> On 2/14/24 23:04, Zi Yan wrote:
>>> @@ -1849,10 +1857,22 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data)
>>> static void compaction_free(struct folio *dst, unsigned long data)
>>> {
>>> struct compact_control *cc = (struct compact_control *)data;
>>> + int order = folio_order(dst);
>>> + struct page *page = &dst->page;
>>> +
>>> + if (folio_put_testzero(dst)) {
>>> + free_pages_prepare_fpi_none(page, order);
>>> +
>>> + INIT_LIST_HEAD(&dst->lru);
>>
>> (is this even needed? I think the state of first parameter of list_add() is
>> never expected to be in particular state?)
>
> There is a __list_add_valid() performing list corruption checks.
Yes, but dst->lru becomes "new" in list_add() and __list_add_valid() and
those never check the contents of new, i.e. new->next or new->prev. We could
have done list_del(&dst->lru) which puts poison values there and then a
list_add() is fine. So dst->lru does not need the init, it's just confusing.
Init is for the list's list_head, not for the list entry.
>>>
>>> - list_add(&dst->lru, &cc->freepages);
>>> - cc->nr_freepages++;
>>> - cc->nr_migratepages += 1 << folio_order(dst);
>>> + list_add(&dst->lru, &cc->freepages[order]);
>>> + cc->nr_freepages += 1 << order;
>>> + cc->nr_migratepages += 1 << order;
>>
>> Hm actually this increment of nr_migratepages should happen even if we lost
>> the free page.
>
> Because compaction_free() indicates the page is not migrated and nr_migratepages
> should be increased regardless.
Yes.
> Will fix it. Thanks.
>
>>> + }
>>> + /*
>>> + * someone else has referenced the page, we cannot take it back to our
>>> + * free list.
>>> + */
>>> }
>
>
> --
> Best Regards,
> Yan, Zi
On 15 Feb 2024, at 15:02, Vlastimil Babka wrote:
> On 2/15/24 18:32, Zi Yan wrote:
>> On 15 Feb 2024, at 11:57, Vlastimil Babka wrote:
>>
>>> On 2/14/24 23:04, Zi Yan wrote:
>>>> @@ -1849,10 +1857,22 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data)
>>>> static void compaction_free(struct folio *dst, unsigned long data)
>>>> {
>>>> struct compact_control *cc = (struct compact_control *)data;
>>>> + int order = folio_order(dst);
>>>> + struct page *page = &dst->page;
>>>> +
>>>> + if (folio_put_testzero(dst)) {
>>>> + free_pages_prepare_fpi_none(page, order);
>>>> +
>>>> + INIT_LIST_HEAD(&dst->lru);
>>>
>>> (is this even needed? I think the state of first parameter of list_add() is
>>> never expected to be in particular state?)
>>
>> There is a __list_add_valid() performing list corruption checks.
>
> Yes, but dst->lru becomes "new" in list_add() and __list_add_valid() and
> those never check the contents of new, i.e. new->next or new->prev. We could
> have done list_del(&dst->lru) which puts poison values there and then a
> list_add() is fine. So dst->lru does not need the init, it's just confusing.
> Init is for the list's list_head, not for the list entry.
Got it. Will remove it.
>>>>
>>>> - list_add(&dst->lru, &cc->freepages);
>>>> - cc->nr_freepages++;
>>>> - cc->nr_migratepages += 1 << folio_order(dst);
>>>> + list_add(&dst->lru, &cc->freepages[order]);
>>>> + cc->nr_freepages += 1 << order;
>>>> + cc->nr_migratepages += 1 << order;
>>>
>>> Hm actually this increment of nr_migratepages should happen even if we lost
>>> the free page.
>>
>> Because compaction_free() indicates the page is not migrated and nr_migratepages
>> should be increased regardless.
>
> Yes.
>
>> Will fix it. Thanks.
>>
>>>> + }
>>>> + /*
>>>> + * someone else has referenced the page, we cannot take it back to our
>>>> + * free list.
>>>> + */
>>>> }
>>
>>
>> --
>> Best Regards,
>> Yan, Zi
--
Best Regards,
Yan, Zi
@@ -66,45 +66,56 @@ static inline void count_compact_events(enum vm_event_item item, long delta)
#define COMPACTION_HPAGE_ORDER (PMD_SHIFT - PAGE_SHIFT)
#endif
-static unsigned long release_freepages(struct list_head *freelist)
+static void split_map_pages(struct list_head *freepages)
{
+ unsigned int i, order;
struct page *page, *next;
- unsigned long high_pfn = 0;
+ LIST_HEAD(tmp_list);
- list_for_each_entry_safe(page, next, freelist, lru) {
- unsigned long pfn = page_to_pfn(page);
- list_del(&page->lru);
- __free_page(page);
- if (pfn > high_pfn)
- high_pfn = pfn;
- }
+ for (order = 0; order < NR_PAGE_ORDERS; order++) {
+ list_for_each_entry_safe(page, next, &freepages[order], lru) {
+ unsigned int nr_pages;
- return high_pfn;
+ list_del(&page->lru);
+
+ nr_pages = 1 << order;
+
+ post_alloc_hook(page, order, __GFP_MOVABLE);
+ if (order)
+ split_page(page, order);
+
+ for (i = 0; i < nr_pages; i++) {
+ list_add(&page->lru, &tmp_list);
+ page++;
+ }
+ }
+ list_splice_init(&tmp_list, &freepages[0]);
+ }
}
-static void split_map_pages(struct list_head *list)
+static unsigned long release_free_list(struct list_head *freepages)
{
- unsigned int i, order, nr_pages;
- struct page *page, *next;
- LIST_HEAD(tmp_list);
-
- list_for_each_entry_safe(page, next, list, lru) {
- list_del(&page->lru);
+ int order;
+ unsigned long high_pfn = 0;
- order = page_private(page);
- nr_pages = 1 << order;
+ for (order = 0; order < NR_PAGE_ORDERS; order++) {
+ struct page *page, *next;
- post_alloc_hook(page, order, __GFP_MOVABLE);
- if (order)
- split_page(page, order);
+ list_for_each_entry_safe(page, next, &freepages[order], lru) {
+ unsigned long pfn = page_to_pfn(page);
- for (i = 0; i < nr_pages; i++) {
- list_add(&page->lru, &tmp_list);
- page++;
+ list_del(&page->lru);
+ /*
+ * Convert free pages into post allocation pages, so
+ * that we can free them via __free_page.
+ */
+ post_alloc_hook(page, order, __GFP_MOVABLE);
+ __free_pages(page, order);
+ if (pfn > high_pfn)
+ high_pfn = pfn;
}
}
-
- list_splice(&tmp_list, list);
+ return high_pfn;
}
#ifdef CONFIG_COMPACTION
@@ -657,7 +668,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc,
nr_scanned += isolated - 1;
total_isolated += isolated;
cc->nr_freepages += isolated;
- list_add_tail(&page->lru, freelist);
+ list_add_tail(&page->lru, &freelist[order]);
if (!strict && cc->nr_migratepages <= cc->nr_freepages) {
blockpfn += isolated;
@@ -722,7 +733,11 @@ isolate_freepages_range(struct compact_control *cc,
unsigned long start_pfn, unsigned long end_pfn)
{
unsigned long isolated, pfn, block_start_pfn, block_end_pfn;
- LIST_HEAD(freelist);
+ int order;
+ struct list_head tmp_freepages[NR_PAGE_ORDERS];
+
+ for (order = 0; order < NR_PAGE_ORDERS; order++)
+ INIT_LIST_HEAD(&tmp_freepages[order]);
pfn = start_pfn;
block_start_pfn = pageblock_start_pfn(pfn);
@@ -753,7 +768,7 @@ isolate_freepages_range(struct compact_control *cc,
break;
isolated = isolate_freepages_block(cc, &isolate_start_pfn,
- block_end_pfn, &freelist, 0, true);
+ block_end_pfn, tmp_freepages, 0, true);
/*
* In strict mode, isolate_freepages_block() returns 0 if
@@ -770,15 +785,15 @@ isolate_freepages_range(struct compact_control *cc,
*/
}
- /* __isolate_free_page() does not map the pages */
- split_map_pages(&freelist);
-
if (pfn < end_pfn) {
/* Loop terminated early, cleanup. */
- release_freepages(&freelist);
+ release_free_list(tmp_freepages);
return 0;
}
+ /* __isolate_free_page() does not map the pages */
+ split_map_pages(tmp_freepages);
+
/* We don't use freelists for anything. */
return pfn;
}
@@ -1494,7 +1509,7 @@ fast_isolate_around(struct compact_control *cc, unsigned long pfn)
if (!page)
return;
- isolate_freepages_block(cc, &start_pfn, end_pfn, &cc->freepages, 1, false);
+ isolate_freepages_block(cc, &start_pfn, end_pfn, cc->freepages, 1, false);
/* Skip this pageblock in the future as it's full or nearly full */
if (start_pfn == end_pfn && !cc->no_set_skip_hint)
@@ -1623,7 +1638,7 @@ static void fast_isolate_freepages(struct compact_control *cc)
nr_scanned += nr_isolated - 1;
total_isolated += nr_isolated;
cc->nr_freepages += nr_isolated;
- list_add_tail(&page->lru, &cc->freepages);
+ list_add_tail(&page->lru, &cc->freepages[order]);
count_compact_events(COMPACTISOLATED, nr_isolated);
} else {
/* If isolation fails, abort the search */
@@ -1700,13 +1715,12 @@ static void isolate_freepages(struct compact_control *cc)
unsigned long isolate_start_pfn; /* exact pfn we start at */
unsigned long block_end_pfn; /* end of current pageblock */
unsigned long low_pfn; /* lowest pfn scanner is able to scan */
- struct list_head *freelist = &cc->freepages;
unsigned int stride;
/* Try a small search of the free lists for a candidate */
fast_isolate_freepages(cc);
if (cc->nr_freepages)
- goto splitmap;
+ return;
/*
* Initialise the free scanner. The starting point is where we last
@@ -1766,7 +1780,7 @@ static void isolate_freepages(struct compact_control *cc)
/* Found a block suitable for isolating free pages from. */
nr_isolated = isolate_freepages_block(cc, &isolate_start_pfn,
- block_end_pfn, freelist, stride, false);
+ block_end_pfn, cc->freepages, stride, false);
/* Update the skip hint if the full pageblock was scanned */
if (isolate_start_pfn == block_end_pfn)
@@ -1807,10 +1821,6 @@ static void isolate_freepages(struct compact_control *cc)
* and the loop terminated due to isolate_start_pfn < low_pfn
*/
cc->free_pfn = isolate_start_pfn;
-
-splitmap:
- /* __isolate_free_page() does not map the pages */
- split_map_pages(freelist);
}
/*
@@ -1821,24 +1831,22 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data)
{
struct compact_control *cc = (struct compact_control *)data;
struct folio *dst;
+ int order = folio_order(src);
- /* this makes migrate_pages() split the source page and retry */
- if (folio_test_large(src) > 0)
- return NULL;
-
- if (list_empty(&cc->freepages)) {
+ if (list_empty(&cc->freepages[order])) {
isolate_freepages(cc);
-
- if (list_empty(&cc->freepages))
+ if (list_empty(&cc->freepages[order]))
return NULL;
}
- dst = list_entry(cc->freepages.next, struct folio, lru);
+ dst = list_first_entry(&cc->freepages[order], struct folio, lru);
list_del(&dst->lru);
- cc->nr_freepages--;
- cc->nr_migratepages -= 1 << folio_order(src);
-
- return dst;
+ post_alloc_hook(&dst->page, order, __GFP_MOVABLE);
+ if (order)
+ prep_compound_page(&dst->page, order);
+ cc->nr_freepages -= 1 << order;
+ cc->nr_migratepages -= 1 << order;
+ return page_rmappable_folio(&dst->page);
}
/*
@@ -1849,10 +1857,22 @@ static struct folio *compaction_alloc(struct folio *src, unsigned long data)
static void compaction_free(struct folio *dst, unsigned long data)
{
struct compact_control *cc = (struct compact_control *)data;
+ int order = folio_order(dst);
+ struct page *page = &dst->page;
+
+ if (folio_put_testzero(dst)) {
+ free_pages_prepare_fpi_none(page, order);
+
+ INIT_LIST_HEAD(&dst->lru);
- list_add(&dst->lru, &cc->freepages);
- cc->nr_freepages++;
- cc->nr_migratepages += 1 << folio_order(dst);
+ list_add(&dst->lru, &cc->freepages[order]);
+ cc->nr_freepages += 1 << order;
+ cc->nr_migratepages += 1 << order;
+ }
+ /*
+ * someone else has referenced the page, we cannot take it back to our
+ * free list.
+ */
}
/* possible outcome of isolate_migratepages */
@@ -2476,6 +2496,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
const bool sync = cc->mode != MIGRATE_ASYNC;
bool update_cached;
unsigned int nr_succeeded = 0;
+ int order;
/*
* These counters track activities during zone compaction. Initialize
@@ -2485,7 +2506,8 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
cc->total_free_scanned = 0;
cc->nr_migratepages = 0;
cc->nr_freepages = 0;
- INIT_LIST_HEAD(&cc->freepages);
+ for (order = 0; order < NR_PAGE_ORDERS; order++)
+ INIT_LIST_HEAD(&cc->freepages[order]);
INIT_LIST_HEAD(&cc->migratepages);
cc->migratetype = gfp_migratetype(cc->gfp_mask);
@@ -2671,7 +2693,7 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
* so we don't leave any returned pages behind in the next attempt.
*/
if (cc->nr_freepages > 0) {
- unsigned long free_pfn = release_freepages(&cc->freepages);
+ unsigned long free_pfn = release_free_list(cc->freepages);
cc->nr_freepages = 0;
VM_BUG_ON(free_pfn == 0);
@@ -2690,7 +2712,6 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
trace_mm_compaction_end(cc, start_pfn, end_pfn, sync, ret);
- VM_BUG_ON(!list_empty(&cc->freepages));
VM_BUG_ON(!list_empty(&cc->migratepages));
return ret;
@@ -447,6 +447,8 @@ extern void prep_compound_page(struct page *page, unsigned int order);
extern void post_alloc_hook(struct page *page, unsigned int order,
gfp_t gfp_flags);
+extern bool free_pages_prepare_fpi_none(struct page *page, unsigned int order);
+
extern int user_min_free_kbytes;
extern void free_unref_page(struct page *page, unsigned int order);
@@ -481,7 +483,7 @@ int split_free_page(struct page *free_page,
* completes when free_pfn <= migrate_pfn
*/
struct compact_control {
- struct list_head freepages; /* List of free pages to migrate to */
+ struct list_head freepages[NR_PAGE_ORDERS]; /* List of free pages to migrate to */
struct list_head migratepages; /* List of pages being migrated */
unsigned int nr_freepages; /* Number of isolated free pages */
unsigned int nr_migratepages; /* Number of pages to migrate */
@@ -1179,6 +1179,12 @@ static __always_inline bool free_pages_prepare(struct page *page,
return true;
}
+__always_inline bool free_pages_prepare_fpi_none(struct page *page,
+ unsigned int order)
+{
+ return free_pages_prepare(page, order, FPI_NONE);
+}
+
/*
* Frees a number of pages from the PCP lists
* Assumes all pages on list are in same zone.