linux-kernel - Re: [PATCH] mm: Fix vmstat after removing NR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <aDhRcXcqctogIITw@tiehlicka>
Date: Thu, 29 May 2025 14:22:09 +0200
From: Michal Hocko <mhocko@...e.com>
To: "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	David Hildenbrand <david@...hat.com>, lorenzo.stoakes@...cle.com,
	Liam.Howlett@...cle.com, vbabka@...e.cz, rppt@...nel.org,
	surenb@...gle.com, linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	Hongyu Ning <hongyu.ning@...ux.intel.com>, stable@...r.kernel.org,
	Christoph Hellwig <hch@....de>, Hannes Reinecke <hare@...e.de>,
	Johannes Thumshirn <johannes.thumshirn@....com>,
	Jens Axboe <axboe@...nel.dk>
Subject: Re: [PATCH] mm: Fix vmstat after removing NR_BOUNCE

On Thu 29-05-25 13:38:32, Kirill A. Shutemov wrote:
> Hongyu noticed that the nr_unaccepted counter kept growing even in the
> absence of unaccepted memory on the machine.
> 
> This happens due to a commit that removed NR_BOUNCE: it removed the
> counter from the enum zone_stat_item, but left it in the vmstat_text
> array.
> 
> As a result, all counters below nr_bounce in /proc/vmstat are
> shifted by one line, causing the numa_hit counter to be labeled as
> nr_unaccepted.
> 
> To fix this issue, remove nr_bounce from the vmstat_text array.
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
> Reported-by: Hongyu Ning <hongyu.ning@...ux.intel.com>
> Fixes: 194df9f66db8 ("mm: remove NR_BOUNCE zone stat")
> Cc: stable@...r.kernel.org
> Cc: Christoph Hellwig <hch@....de>
> Cc: Hannes Reinecke <hare@...e.de>
> Cc: Johannes Thumshirn <johannes.thumshirn@....com>
> Cc: Jens Axboe <axboe@...nel.dk>

Acked-by: Michal Hocko <mhocko@...e.com>
Unfortunatelly a common mistake to make. I have seen you have a followup
fix with a stricter build time check. Will have a look.

Thanks!

> ---
>  mm/vmstat.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/mm/vmstat.c b/mm/vmstat.c
> index 4c268ce39ff2..ae9882063d89 100644
> --- a/mm/vmstat.c
> +++ b/mm/vmstat.c
> @@ -1201,7 +1201,6 @@ const char * const vmstat_text[] = {
>  	"nr_zone_unevictable",
>  	"nr_zone_write_pending",
>  	"nr_mlock",
> -	"nr_bounce",
>  #if IS_ENABLED(CONFIG_ZSMALLOC)
>  	"nr_zspages",
>  #endif
> -- 
> 2.47.2

-- 
Michal Hocko
SUSE Labs