Re: Still seeing Failed assertion: "p[i] == 0" on armv7 buildworld [kib committed git: 72a447d0bc76 that should help]

Konstantin Belousov <kib_at_FreeBSD.org> wrote on
Date: Mon, 24 Nov 2025 18:09:09 UTC :

> The branch main has been updated by kib:
> 
> URL: https://cgit.FreeBSD.org/src/commit/?id=72a447d0bc768c7fe8a9c972f710c75afebd581b
> 
> commit 72a447d0bc768c7fe8a9c972f710c75afebd581b
> Author:     Konstantin Belousov <kib@FreeBSD.org>
> AuthorDate: 2025-11-22 20:39:27 +0000
> Commit:     Konstantin Belousov <kib@FreeBSD.org>
> CommitDate: 2025-11-24 18:08:31 +0000
> 
>     vm_object_page_remove(): clear pager even if there is no resident pages
>     
>     Swap pager might still carry the data.
>     
>     Debugging help from:    mmel
>     Reviewed by:    alc
>     Sponsored by:   The FreeBSD Foundation
>     MFC after:      1 week
>     Differential revision:  https://reviews.freebsd.org/D53891
> ---
>  sys/vm/vm_object.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
> index 5b4517d2bf0c..413ba5459e3d 100644
> --- a/sys/vm/vm_object.c
> +++ b/sys/vm/vm_object.c
> @@ -1988,7 +1988,7 @@ vm_object_page_remove(vm_object_t object, vm_pindex_t start, vm_pindex_t end,
>  	    (options & (OBJPR_CLEANONLY | OBJPR_NOTMAPPED)) == OBJPR_NOTMAPPED,
>  	    ("vm_object_page_remove: illegal options for object %p", object));
>  	if (object->resident_page_count == 0)
> -		return;
> +		goto remove_pager;
>  	vm_object_pip_add(object, 1);
>  	vm_page_iter_limit_init(&pages, object, end);
>  again:
> @@ -2061,6 +2061,7 @@ wired:
>  	}
>  	vm_object_pip_wakeup(object);
>  
> +remove_pager:
>  	vm_pager_freespace(object, start, (end == 0 ? object->size : end) -
>  	    start);
>  }


There is still some question about which way another test should
be in vm_object_coalesce. But the above should be necessary,
even if it is not always sufficient to prevent all potential
failure types.

See https://reviews.freebsd.org/D53891 for the status of what
may be a pending additional change.


===
Mark Millard
marklmi at yahoo.com