Re: [PATCH] Documentation: incorrect formula to calculate CommitLimit value

[Randy Dunlap <rdunlap@infradead.org>]

On 05/22/2014 05:04 AM, Petr Oros wrote:
> The formula to calculate "CommitLimit" value mentioned in kernel documentation is incorrect.
> Right formula is: CommitLimit = ([total RAM pages] - [total huge TLB pages]) * overcommit_ratio / 100 + [total swap pages]
> 
> Signed-off-by: Petr Oros <poros@redhat.com>

Acked-by: Randy Dunlap <rdunlap@infradead.org>

Jiri, please grab this patch.

Thanks.


> ---
>  Documentation/filesystems/proc.txt | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
> index 8b9cd8e..b58d764 100644
> --- a/Documentation/filesystems/proc.txt
> +++ b/Documentation/filesystems/proc.txt
> @@ -854,7 +854,8 @@ WritebackTmp: Memory used by FUSE for temporary writeback buffers
>                if strict overcommit accounting is enabled (mode 2 in
>                'vm.overcommit_memory').
>                The CommitLimit is calculated with the following formula:
> -              CommitLimit = ('vm.overcommit_ratio' * Physical RAM) + Swap
> +              CommitLimit = ([total RAM pages] - [total huge TLB pages]) *
> +                             overcommit_ratio / 100 + [total swap pages]
>                For example, on a system with 1G of physical RAM and 7G
>                of swap with a `vm.overcommit_ratio` of 30 it would
>                yield a CommitLimit of 7.3G.
> 


-- 
~Randy