• Vlastimil Babka's avatar
    mm, page_owner: dump page owner info from dump_page() · 4e462112
    Vlastimil Babka authored
    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: default avatarVlastimil Babka <vbabka@suse.cz>
    Acked-by: default avatarMichal 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: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    4e462112
page_owner.h 2.13 KB