From f788d97308a787855e2abc9a0400fcf287a0ac83 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Tue, 15 Mar 2016 14:56:18 -0700 Subject: mm, page_owner: track and print last migrate reason During migration, page_owner info is now copied with the rest of the page, so the stacktrace leading to free page allocation during migration is overwritten. For debugging purposes, it might be however useful to know that the page has been migrated since its initial allocation. This might happen many times during the lifetime for different reasons and fully tracking this, especially with stacktraces would incur extra memory costs. As a compromise, store and print the migrate_reason of the last migration that occurred to the page. This is enough to distinguish compaction, numa balancing etc. Example page_owner entry after the patch: Page allocated via order 0, mask 0x24200ca(GFP_HIGHUSER_MOVABLE) PFN 628753 type Movable Block 1228 type Movable Flags 0x1fffff80040030(dirty|lru|swapbacked) [] __alloc_pages_nodemask+0x134/0x230 [] alloc_pages_vma+0xb5/0x250 [] shmem_alloc_page+0x61/0x90 [] shmem_getpage_gfp+0x678/0x960 [] shmem_fallocate+0x329/0x440 [] vfs_fallocate+0x140/0x230 [] SyS_fallocate+0x44/0x70 [] entry_SYSCALL_64_fastpath+0x12/0x71 Page has been migrated, last migrate reason: compaction Change-Id: I9c93f9f91fa71feaea1505d80ee56caf8daf5562 Signed-off-by: Vlastimil Babka Cc: Joonsoo Kim Cc: Minchan Kim Cc: Sasha Levin Cc: "Kirill A. Shutemov" Cc: Mel Gorman Cc: Michal Hocko Cc: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Git-commit: 7cd12b4abfd2f8f42414c520bbd051a5b7dc7a8c Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git [guptap@codeaurora.org: resolve trivial merge conflicts] Signed-off-by: Prakash Gupta --- mm/debug.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'mm/debug.c') diff --git a/mm/debug.c b/mm/debug.c index 5cf26f8c69a3..52e35fa3462c 100644 --- a/mm/debug.c +++ b/mm/debug.c @@ -9,6 +9,17 @@ #include #include #include +#include + +char *migrate_reason_names[MR_TYPES] = { + "compaction", + "memory_failure", + "memory_hotplug", + "syscall_or_cpuset", + "mempolicy_mbind", + "numa_misplaced", + "cma", +}; static const struct trace_print_flags pageflag_names[] = { {1UL << PG_locked, "locked" }, -- cgit v1.2.3