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| author |   Vlastimil Babka <vbabka@suse.cz> | 2019-07-11 20:55:13 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2019-07-12 11:05:43 -0700 |
| commit | 3972f6bb1c6ae1d32dcf2e4ff635d24b77f26dcb (patch) | |
| tree | 24a0c4a24d8e1afdcb7ca5dd088c1bd4d191a9b9 /include/linux/page-flags.h | |
| parent | mm, page_alloc: more extensive free page checking with debug_pagealloc (diff) | |
| download | linux-dev-3972f6bb1c6ae1d32dcf2e4ff635d24b77f26dcb.tar.xz linux-dev-3972f6bb1c6ae1d32dcf2e4ff635d24b77f26dcb.zip | |
mm, debug_pagealloc: use a page type instead of page_ext flag
When debug_pagealloc is enabled, we currently allocate the page_ext
array to mark guard pages with the PAGE_EXT_DEBUG_GUARD flag. Now that
we have the page_type field in struct page, we can use that instead, as
guard pages are neither PageSlab nor mapped to userspace. This reduces
memory overhead when debug_pagealloc is enabled and there are no other
features requiring the page_ext array.
Link: http://lkml.kernel.org/r/20190603143451.27353-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 9f8712a4b1a5..b848517da64c 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -703,6 +703,7 @@ PAGEFLAG_FALSE(DoubleMap) #define PG_offline 0x00000100 #define PG_kmemcg 0x00000200 #define PG_table 0x00000400 +#define PG_guard 0x00000800 #define PageType(page, flag) \ ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) @@ -754,6 +755,11 @@ PAGE_TYPE_OPS(Kmemcg, kmemcg) */ PAGE_TYPE_OPS(Table, table) +/* + * Marks guardpages used with debug_pagealloc. + */ +PAGE_TYPE_OPS(Guard, guard) + extern bool is_free_buddy_page(struct page *page); __PAGEFLAG(Isolated, isolated, PF_ANY); |