This is a crash utility extension module to display Linux kernel's page owner information. To use the module, the page owner facility must be enabled by the kernel command-line parameter "page_owner=on".
To build the module from the top-level crash-<version> directory, enter:
$ cp <path-to>/page_owner.c extensions
$ make extensions
To load the module's commands to a running crash session, enter:
crash> extend <path-to>/page_owner.so
To show the module's commands, enter:
crash> extend
SHARED OBJECT COMMANDS
<path-to>/page_owner.so owner
The module has only a command: owner.
NAME
owner - dump page owner information
SYNOPSIS
owner [-p] address..
owner -l|-L [count]
DESCRIPTION
This command dumps the page owner information of a specified address.
-l list page owner information for allocated pages.
-L list page owner information for allocated and freed pages.
(this option is available only on Linux 5.4, RHEL8.5 and later.)
-p address argument is a physical address.
address a kernel virtual address by default, a physical address with -p.
count number of pages to display for -l and -L option.
EXAMPLES
Dump the page owner information of a specified page address:
crash> owner ffff892b73200000
PFN 471552(0x73200) paddr 73200000 vaddr ffff892b73200000 page fffff4bec1cc8000 page_owner ffff892c024c8008
Page allocated via order 9, mask 0x346cca, pid 46265, tgid 46265 (bash), ts 88704902141361 ns, free_ts 23514284799158 ns
[alloc]
get_page_from_freelist+0x33e
__alloc_pages+0xe6
alloc_buddy_huge_page+0x43
alloc_fresh_huge_page+0x16f
alloc_pool_huge_page+0x76
set_max_huge_pages+0x198
__nr_hugepages_store_common+0x48
hugetlb_sysctl_handler_common+0xdf
proc_sys_call_handler+0x162
new_sync_write+0xfc
vfs_write+0x1ef
ksys_write+0x5f
do_syscall_64+0x59
entry_SYSCALL_64_after_hwframe+0x63
free
free_pcp_prepare+0x142
free_unref_page_list+0x92
release_pages+0x16d
tlb_flush_mmu+0x4b
zap_pte_range+0x808
zap_pmd_range+0x141
unmap_page_range+0x2c6
unmap_vmas+0x78
exit_mmap+0xa5
mmput+0x5a
exit_mm+0xb8
do_exit+0x1f3
do_group_exit+0x2d
__x64_sys_exit_group+0x14
do_syscall_64+0x59
entry_SYSCALL_64_after_hwframe+0x63
List the page owner information of allocated pages:
crash> owner -l
PFN 256(0x100) paddr 100000 page_owner ffff892c00804008
Page allocated via order 7, mask 0xcc1, pid 1, tgid 1 (swapper/0), ts 129969032 ns, free_ts 0 ns
[alloc]
get_page_from_freelist+0x33e
__alloc_pages+0xe6
alloc_page_interleave+0xf
atomic_pool_expand+0x11c
__dma_atomic_pool_init+0x45
dma_atomic_pool_init+0xaf
do_one_initcall+0x41
do_initcalls+0xc6
kernel_init_freeable+0x153
kernel_init+0x16
ret_from_fork+0x1f
PFN 4096(0x1000) paddr 1000000 page_owner ffff892c00840008
Page allocated via order 9, mask 0x3c24ca, pid 45, tgid 45 (khugepaged), ts 96573977813114 ns, free_ts 0 ns
[alloc]
get_page_from_freelist+0x33e
__alloc_pages+0xe6
collapse_huge_page+0x8b
khugepaged_scan_pmd+0x32b
...
- RHEL8.3 to RHEL9.4 (x86_64)
- 4.18 to 6.11 (x86_64)
- Kazuhito Hagio <[email protected]>