diff options
| author | Zi Yan <ziy@nvidia.com> | 2024-02-20 19:32:19 +0100 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-02-24 02:48:33 +0100 |
| commit | 733aea0b3a7bba0451dfc19322665de13a5b7af4 (patch) | |
| tree | d32337243b2b5aeca33bc2fb7592cdb22b8d1368 /mm/internal.h | |
| parent | mm/compaction: enable compacting >0 order folios. (diff) | |
| download | linux-733aea0b3a7bba0451dfc19322665de13a5b7af4.tar.xz linux-733aea0b3a7bba0451dfc19322665de13a5b7af4.zip | |
mm/compaction: add support for >0 order folio memory compaction.
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.
Link: https://lkml.kernel.org/r/20240220183220.1451315-4-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/internal.h')
| -rw-r--r-- | mm/internal.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/internal.h b/mm/internal.h index 1e29c5821a1d..93e229112045 100644 --- 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(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 */ |