On 20 May 2022, at 15:41, Qian Cai wrote:

> On Fri, May 20, 2022 at 10:13:51AM -0400, Zi Yan wrote:
>> Also, do you mind providing the page dump of the 512-page compound page? I would like
>> to know what page caused the issue.
>
>  page last allocated via order 9, migratetype Movable, gfp_mask 0x3c24ca(GFP_TRANSHUGE|__GFP_THISNODE), pid 831, tgid 831 (khugepaged), ts 3899865924520, free_ts 3821953009040
>   post_alloc_hook
>   get_page_from_freelist
>   __alloc_pages
>   khugepaged_alloc_page
>   collapse_huge_page
>   khugepaged_scan_pmd
>   khugepaged_scan_mm_slot
>   khugepaged
>   kthread
>   ret_from_fork
>  page last free stack trace:
>   free_pcp_prepare
>   free_unref_page
>   free_compound_page
>   free_transhuge_page
>   __put_compound_page
>   release_pages
>   free_pages_and_swap_cache
>   tlb_batch_pages_flush
>   tlb_finish_mmu
>   exit_mmap
>   __mmput
>   mmput
>   exit_mm
>   do_exit
>   do_group_exit
>   __arm64_sys_exit_group

Do you have the page information like refcount, map count, mapping, index, and
page flags? That would be more helpful. Thanks.

I cannot reproduce it locally after hundreds of iterations of flip_mem.py on my
x86_64 VM and bare metal.

What ARM machine are you using? I wonder if I am able to get one locally.

Thanks.

--
Best Regards,
Yan, Zi