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-rw-r--r--Documentation/mm/page_owner.rst73
1 files changed, 38 insertions, 35 deletions
diff --git a/Documentation/mm/page_owner.rst b/Documentation/mm/page_owner.rst
index 0d0334cd5179..3a45a20fc05a 100644
--- a/Documentation/mm/page_owner.rst
+++ b/Documentation/mm/page_owner.rst
@@ -24,10 +24,10 @@ fragmentation statistics can be obtained through gfp flag information of
each page. It is already implemented and activated if page owner is
enabled. Other usages are more than welcome.
-It can also be used to show all the stacks and their outstanding
-allocations, which gives us a quick overview of where the memory is going
-without the need to screen through all the pages and match the allocation
-and free operation.
+It can also be used to show all the stacks and their current number of
+allocated base pages, which gives us a quick overview of where the memory
+is going without the need to screen through all the pages and match the
+allocation and free operation.
page owner is disabled by default. So, if you'd like to use it, you need
to add "page_owner=on" to your boot cmdline. If the kernel is built
@@ -75,42 +75,45 @@ Usage
cat /sys/kernel/debug/page_owner_stacks/show_stacks > stacks.txt
cat stacks.txt
- prep_new_page+0xa9/0x120
- get_page_from_freelist+0x7e6/0x2140
- __alloc_pages+0x18a/0x370
- new_slab+0xc8/0x580
- ___slab_alloc+0x1f2/0xaf0
- __slab_alloc.isra.86+0x22/0x40
- kmem_cache_alloc+0x31b/0x350
- __khugepaged_enter+0x39/0x100
- dup_mmap+0x1c7/0x5ce
- copy_process+0x1afe/0x1c90
- kernel_clone+0x9a/0x3c0
- __do_sys_clone+0x66/0x90
- do_syscall_64+0x7f/0x160
- entry_SYSCALL_64_after_hwframe+0x6c/0x74
- stack_count: 234
+ post_alloc_hook+0x177/0x1a0
+ get_page_from_freelist+0xd01/0xd80
+ __alloc_pages+0x39e/0x7e0
+ allocate_slab+0xbc/0x3f0
+ ___slab_alloc+0x528/0x8a0
+ kmem_cache_alloc+0x224/0x3b0
+ sk_prot_alloc+0x58/0x1a0
+ sk_alloc+0x32/0x4f0
+ inet_create+0x427/0xb50
+ __sock_create+0x2e4/0x650
+ inet_ctl_sock_create+0x30/0x180
+ igmp_net_init+0xc1/0x130
+ ops_init+0x167/0x410
+ setup_net+0x304/0xa60
+ copy_net_ns+0x29b/0x4a0
+ create_new_namespaces+0x4a1/0x820
+ nr_base_pages: 16
...
...
echo 7000 > /sys/kernel/debug/page_owner_stacks/count_threshold
cat /sys/kernel/debug/page_owner_stacks/show_stacks> stacks_7000.txt
cat stacks_7000.txt
- prep_new_page+0xa9/0x120
- get_page_from_freelist+0x7e6/0x2140
- __alloc_pages+0x18a/0x370
- alloc_pages_mpol+0xdf/0x1e0
- folio_alloc+0x14/0x50
- filemap_alloc_folio+0xb0/0x100
- page_cache_ra_unbounded+0x97/0x180
- filemap_fault+0x4b4/0x1200
- __do_fault+0x2d/0x110
- do_pte_missing+0x4b0/0xa30
- __handle_mm_fault+0x7fa/0xb70
- handle_mm_fault+0x125/0x300
- do_user_addr_fault+0x3c9/0x840
- exc_page_fault+0x68/0x150
- asm_exc_page_fault+0x22/0x30
- stack_count: 8248
+ post_alloc_hook+0x177/0x1a0
+ get_page_from_freelist+0xd01/0xd80
+ __alloc_pages+0x39e/0x7e0
+ alloc_pages_mpol+0x22e/0x490
+ folio_alloc+0xd5/0x110
+ filemap_alloc_folio+0x78/0x230
+ page_cache_ra_order+0x287/0x6f0
+ filemap_get_pages+0x517/0x1160
+ filemap_read+0x304/0x9f0
+ xfs_file_buffered_read+0xe6/0x1d0 [xfs]
+ xfs_file_read_iter+0x1f0/0x380 [xfs]
+ __kernel_read+0x3b9/0x730
+ kernel_read_file+0x309/0x4d0
+ __do_sys_finit_module+0x381/0x730
+ do_syscall_64+0x8d/0x150
+ entry_SYSCALL_64_after_hwframe+0x62/0x6a
+ nr_base_pages: 20824
...
cat /sys/kernel/debug/page_owner > page_owner_full.txt