Re: [PATCH v3] docs: proc.rst: meminfo: briefly describe gaps in memory accounting

From: Vlastimil Babka <vbabka@suse.cz>
To: Mike Rapoport <rppt@kernel.org>, Jonathan Corbet <corbet@lwn.net>
Cc: Alexey Dobriyan <adobriyan@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Eric Dumazet <eric.dumazet@gmail.com>,
	Matthew Wilcox <willy@infradead.org>,
	Michal Hocko <mhocko@suse.com>,
	Mike Rapoport <rppt@linux.ibm.com>,
	linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	netdev@vger.kernel.org
Subject: Re: [PATCH v3] docs: proc.rst: meminfo: briefly describe gaps in memory accounting
Date: Fri, 23 Apr 2021 16:27:45 +0200	[thread overview]
Message-ID: <d047c2fb-d15a-d094-3256-ea6eeff2d7c7@suse.cz> (raw)
In-Reply-To: <20210421061127.1182723-1-rppt@kernel.org>

On 4/21/21 8:11 AM, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
> 
> Add a paragraph that explains that it may happen that the counters in
> /proc/meminfo do not add up to the overall memory usage.
> 
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>

Acked-by: Vlastimil Babka <vbabka@suse.cz>

Thanks.

> ---
> v3:
> * Add sentense about counters overlap
> * Use wording suggested by Matthew
> 
> v2: Link: https://lore.kernel.org/lkml/20210420121354.1160437-1-rppt@kernel.org
> * Add brief changelog
> * Fix typo
> * Update example about network memory usage according to Eric's comment at
> 
> https://lore.kernel.org/lkml/CANn89iKprp7WYeZy4RRO5jHykprnSCcVBc7Tk14Ui_MA9OK7Fg@mail.gmail.com
> 
> v1: Link: https://lore.kernel.org/lkml/20210420085105.1156640-1-rppt@kernel.org
>  Documentation/filesystems/proc.rst | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
> index 48fbfc336ebf..0a07a5025571 100644
> --- a/Documentation/filesystems/proc.rst
> +++ b/Documentation/filesystems/proc.rst
> @@ -929,8 +929,15 @@ meminfo
>  ~~~~~~~
>  
>  Provides information about distribution and utilization of memory.  This
> -varies by architecture and compile options.  The following is from a
> -16GB PIII, which has highmem enabled.  You may not have all of these fields.
> +varies by architecture and compile options.  Some of the counters reported
> +here overlap.  The memory reported by the non overlapping counters may not
> +add up to the overall memory usage and the difference for some workloads
> +can be substantial.  In many cases there are other means to find out
> +additional memory using subsystem specific interfaces, for instance
> +/proc/net/sockstat for TCP memory allocations.
> +
> +The following is from a 16GB PIII, which has highmem enabled.
> +You may not have all of these fields.
>  
>  ::
>  
> 