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ANDROID: mm: page_alloc: skip dump pages for freeable page

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We have seen following dumps from alloc_contig_dump_pages.

05-20 20:04:41.847  1000   503   503 W page    : 00000000691ab336 refcount:1 mapcount:0 mapping:0000000000000000 index:0x72aa2d7 pfn:0x9e912e
05-20 20:04:41.847  1000   503   503 W anon flags: 0x8000000000080004(uptodate|swapbacked)
05-20 20:04:41.847  1000   503   503 W raw     : 8000000000080004 ffffffff25844b48 ffffffff25844bc8 ffffff89824e46c1
05-20 20:04:41.847  1000   503   503 W raw     : 00000000072aa2d7 0000000000000000 00000001ffffffff 0000000000000000
05-20 20:04:41.847  1000   503   503 W         : page dumped because: migration failure
05-20 20:04:41.847  1000   503   503 F         : page_pinner info is not present (never set?)
05-20 20:04:41.847  1000   503   503 W page    : 0000000099d95f64 refcount:1 mapcount:0 mapping:0000000000000000 index:0x72aa2d6 pfn:0x9e912d
05-20 20:04:41.847  1000   503   503 W anon flags: 0x8000000000080004(uptodate|swapbacked)
05-20 20:04:41.847  1000   503   503 W raw     : 8000000000080004 ffffffff25844b08 ffffffff25844b88 ffffff89824e46c1
05-20 20:04:41.847  1000   503   503 W raw     : 00000000072aa2d6 0000000000000000 00000001ffffffff 0000000000000000
05-20 20:04:41.847  1000   503   503 W         : page dumped because: migration failure
05-20 20:04:41.847  1000   503   503 F         : page_pinner info is not present (never set?)
05-20 20:04:41.847  1000   503   503 W page    : 000000009af39924 refcount:1 mapcount:0 mapping:0000000000000000 index:0x72aa2d5 pfn:0x9e912c
05-20 20:04:41.847  1000   503   503 W anon flags: 0x8000000000080004(uptodate|swapbacked)
05-20 20:04:41.847  1000   503   503 W raw     : 8000000000080004 ffffffff25844ac8 ffffffff25844b48 ffffff89824e46c1
05-20 20:04:41.847  1000   503   503 W raw     : 00000000072aa2d5 0000000000000000 00000001ffffffff 0000000000000000
05-20 20:04:41.847  1000   503   503 W         : page dumped because: migration failure
..
..

It means those pages would be temporarily pinnned during migration so the migration
failed but putback_movable_pages will end up freeing them since their page refcount
are 1 now. Thus, it doesn't deserve to dump them for the debugging aid.

Bug: 188908895
Signed-off-by: Minchan Kim <minchan@google.com>
Change-Id: I24092f0e53a3154443b9d6786413c4714ae853e8
This commit is contained in:
Minchan Kim
2021-05-21 11:02:33 -07:00
parent 72488b3be4
commit 0249af9c0e
1 changed files with 11 additions and 1 deletions
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12
mm/page_alloc.c
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@@ -8546,11 +8546,21 @@ static void alloc_contig_dump_pages(struct list_head *page_list)
if (DYNAMIC_DEBUG_BRANCH(descriptor)) { if (DYNAMIC_DEBUG_BRANCH(descriptor)) {
struct page *page; struct page *page;
unsigned long nr_skip = 0;
unsigned long nr_pages = 0;
dump_stack(); dump_stack();
list_for_each_entry(page, page_list, lru) list_for_each_entry(page, page_list, lru) {
nr_pages++;
/* The page will be freed by putback_movable_pages soon */
if (page_count(page) == 1) {
nr_skip++;
continue;
}
dump_page(page, "migration failure"); dump_page(page, "migration failure");
} }
pr_warn("total dump_pages %u skipping %u\n", nr_pages, nr_skip);
}
} }
#else #else
static inline void alloc_contig_dump_pages(struct list_head *page_list) static inline void alloc_contig_dump_pages(struct list_head *page_list)