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authorVlastimil Babka <vbabka@suse.cz>2016-03-15 14:56:21 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-15 16:55:16 -0700
commit4e462112e98f9ad6dd62e160f8b14c7df5fed2fc (patch)
tree0551f3177bbed8ec2a48af4a84e27a7f308bb2db /include/linux/page_owner.h
parent7cd12b4abfd2f8f42414c520bbd051a5b7dc7a8c (diff)
downloadlwn-4e462112e98f9ad6dd62e160f8b14c7df5fed2fc.tar.gz
lwn-4e462112e98f9ad6dd62e160f8b14c7df5fed2fc.zip
mm, page_owner: dump page owner info from dump_page()
The page_owner mechanism is useful for dealing with memory leaks. By reading /sys/kernel/debug/page_owner one can determine the stack traces leading to allocations of all pages, and find e.g. a buggy driver. This information might be also potentially useful for debugging, such as the VM_BUG_ON_PAGE() calls to dump_page(). So let's print the stored info from dump_page(). Example output: page:ffffea000292f1c0 count:1 mapcount:0 mapping:ffff8800b2f6cc18 index:0x91d flags: 0x1fffff8001002c(referenced|uptodate|lru|mappedtodisk) page dumped because: VM_BUG_ON_PAGE(1) page->mem_cgroup:ffff8801392c5000 page allocated via order 0, migratetype Movable, gfp_mask 0x24213ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD|__GFP_NOWARN|__GFP_NORETRY) [<ffffffff811682c4>] __alloc_pages_nodemask+0x134/0x230 [<ffffffff811b40c8>] alloc_pages_current+0x88/0x120 [<ffffffff8115e386>] __page_cache_alloc+0xe6/0x120 [<ffffffff8116ba6c>] __do_page_cache_readahead+0xdc/0x240 [<ffffffff8116bd05>] ondemand_readahead+0x135/0x260 [<ffffffff8116be9c>] page_cache_async_readahead+0x6c/0x70 [<ffffffff811604c2>] generic_file_read_iter+0x3f2/0x760 [<ffffffff811e0dc7>] __vfs_read+0xa7/0xd0 page has been migrated, last migrate reason: compaction Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/page_owner.h')
-rw-r--r--include/linux/page_owner.h9
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
index 555893bf13d7..46f1b939948c 100644
--- a/include/linux/page_owner.h
+++ b/include/linux/page_owner.h
@@ -13,6 +13,7 @@ extern void __set_page_owner(struct page *page,
extern gfp_t __get_page_owner_gfp(struct page *page);
extern void __copy_page_owner(struct page *oldpage, struct page *newpage);
extern void __set_page_owner_migrate_reason(struct page *page, int reason);
+extern void __dump_page_owner(struct page *page);
static inline void reset_page_owner(struct page *page, unsigned int order)
{
@@ -44,6 +45,11 @@ static inline void set_page_owner_migrate_reason(struct page *page, int reason)
if (static_branch_unlikely(&page_owner_inited))
__set_page_owner_migrate_reason(page, reason);
}
+static inline void dump_page_owner(struct page *page)
+{
+ if (static_branch_unlikely(&page_owner_inited))
+ __dump_page_owner(page);
+}
#else
static inline void reset_page_owner(struct page *page, unsigned int order)
{
@@ -62,5 +68,8 @@ static inline void copy_page_owner(struct page *oldpage, struct page *newpage)
static inline void set_page_owner_migrate_reason(struct page *page, int reason)
{
}
+static inline void dump_page_owner(struct page *page)
+{
+}
#endif /* CONFIG_PAGE_OWNER */
#endif /* __LINUX_PAGE_OWNER_H */