With the new format strings for flags, we can now provide symbolic page and gfp flags in the /sys/kernel/debug/page_owner file. This replaces the positional printing of page flags as single letters, which might have looked nicer, but was limited to a subset of flags, and required the user to remember the letters. Example of the adjusted format: Page allocated via order 0, mask 0x24213ca(GFP_HIGHUSER_MOVABLE|GFP_COLD|GFP_NOWARN|GFP_NORETRY) PFN 674308 type Movable Block 1317 type Movable Flags 0x1fffff80010068(uptodate|lru|active|mappedtodisk) [<ffffffff81164e9a>] __alloc_pages_nodemask+0x15a/0xa30 [<ffffffff811ab938>] alloc_pages_current+0x88/0x120 [<ffffffff8115bc46>] __page_cache_alloc+0xe6/0x120 [<ffffffff81168b9b>] __do_page_cache_readahead+0xdb/0x200 [<ffffffff81168df5>] ondemand_readahead+0x135/0x260 [<ffffffff81168f8c>] page_cache_async_readahead+0x6c/0x70 [<ffffffff8115d5f8>] generic_file_read_iter+0x378/0x590 [<ffffffff811d12a7>] __vfs_read+0xa7/0xd0 Page has been migrated, last migrate reason: compaction Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Minchan Kim <minchan@xxxxxxxxxx> Cc: Sasha Levin <sasha.levin@xxxxxxxxxx> Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> --- mm/page_owner.c | 20 +++++--------------- 1 file changed, 5 insertions(+), 15 deletions(-) diff --git a/mm/page_owner.c b/mm/page_owner.c index 313251f36d86..011377548b4f 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -135,8 +135,9 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, return -ENOMEM; ret = snprintf(kbuf, count, - "Page allocated via order %u, mask 0x%x\n", - page_ext->order, page_ext->gfp_mask); + "Page allocated via order %u, mask %#x(%pgg)\n", + page_ext->order, page_ext->gfp_mask, + &page_ext->gfp_mask); if (ret >= count) goto err; @@ -145,23 +146,12 @@ print_page_owner(char __user *buf, size_t count, unsigned long pfn, pageblock_mt = get_pfnblock_migratetype(page, pfn); page_mt = gfpflags_to_migratetype(page_ext->gfp_mask); ret += snprintf(kbuf + ret, count - ret, - "PFN %lu type %s Block %lu type %s Flags %s%s%s%s%s%s%s%s%s%s%s%s\n", + "PFN %lu type %s Block %lu type %s Flags %#lx(%pgp)\n", pfn, migratetype_names[page_mt], pfn >> pageblock_order, migratetype_names[pageblock_mt], - PageLocked(page) ? "K" : " ", - PageError(page) ? "E" : " ", - PageReferenced(page) ? "R" : " ", - PageUptodate(page) ? "U" : " ", - PageDirty(page) ? "D" : " ", - PageLRU(page) ? "L" : " ", - PageActive(page) ? "A" : " ", - PageSlab(page) ? "S" : " ", - PageWriteback(page) ? "W" : " ", - PageCompound(page) ? "C" : " ", - PageSwapCache(page) ? "B" : " ", - PageMappedToDisk(page) ? "M" : " "); + page->flags, &page->flags); if (ret >= count) goto err; -- 2.6.3 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>