The patch titled Subject: mm/debug: handle page->mapping better in dump_page has been added to the -mm tree. Its filename is mm-handle-page-mapping-better-in-dump_page.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-handle-page-mapping-better-in-dump_page.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-handle-page-mapping-better-in-dump_page.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> Subject: mm/debug: handle page->mapping better in dump_page Patch series "Improvements for dump_page()", v2. Here's a sample dump of a pagecache tail page with all of the patches applied: page:000000006d1c49ca refcount:6 mapcount:0 mapping:00000000136b8d90 index:0x109 pfn:0x6c645 head:000000008bd38076 order:2 compound_mapcount:0 compound_pincount:0 aops:xfs_address_space_operations ino:800042 dentry name:"fd" flags: 0x4000000000012014(uptodate|lru|private|head) raw: 4000000000000000 ffffd46ac1b19101 ffffffff00000202 dead000000000004 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 head: 4000000000012014 ffffd46ac1b1bbc8 ffffd46ac1b1bc08 ffff91976f659560 head: 0000000000000108 ffff919773220680 00000006ffffffff 0000000000000000 page dumped because: testing This patch (of 6): If we can't call page_mapping() to get the page mapping, handle the anon/ksm/movable bits correctly. Link: http://lkml.kernel.org/r/20200709202117.7216-1-willy@xxxxxxxxxxxxx Link: http://lkml.kernel.org/r/20200709202117.7216-2-willy@xxxxxxxxxxxxx Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: William Kucharski <william.kucharski@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: John Hubbard <jhubbard@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/debug.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/mm/debug.c~mm-handle-page-mapping-better-in-dump_page +++ a/mm/debug.c @@ -70,7 +70,12 @@ void __dump_page(struct page *page, cons if (page < head || (page >= head + MAX_ORDER_NR_PAGES)) { /* Corrupt page, cannot call page_mapping */ - mapping = page->mapping; + unsigned long tmp = (unsigned long)page->mapping; + + if (tmp & PAGE_MAPPING_ANON) + mapping = NULL; + else + mapping = (void *)(tmp & ~PAGE_MAPPING_FLAGS); head = page; compound = false; } else { _ Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are mm-handle-page-mapping-better-in-dump_page.patch mm-dump-compound-page-information-on-a-second-line.patch mm-print-head-flags-in-dump_page.patch mm-switch-dump_page-to-get_kernel_nofault.patch mm-print-the-inode-number-in-dump_page.patch mm-print-hashed-address-of-struct-page.patch vmalloc-convert-to-xarray.patch mm-store-compound_nr-as-well-as-compound_order.patch mm-move-page-flags-include-to-top-of-file.patch mm-add-thp_order.patch mm-add-thp_size.patch mm-replace-hpage_nr_pages-with-thp_nr_pages.patch mm-add-thp_head.patch mm-introduce-offset_in_thp.patch