Re: That greedy Linux VM cache

["Austin S. Hemmelgarn" <ahferroin7@gmail.com>]

On 01/31/2014 09:47 AM, Igor Podlesny wrote:
> On 31 January 2014 00:58, Igor Podlesny <for.poige+linux@gmail.com> wrote:
> [...]
>>  While I'm thinking about moving system back to XFS...
> 
>    Well, it helped just a bit. The whole picture remains, so it's not
> Btrfs' issue, but seemingly Linux VM's one. The problem can be briefly
> described as "if allowed to swap (swappiness != 0), VM would rather
> start swapping, than reduce cache size which holds ~ 25 % of RAM".
> Even more briefly it's stated in the Subject.
> 
>    From user's point of view, it looks like the system is being
> heavily swapped (and can be easily misinterpreted as it), but actually
> the most disk activity is permanent _reading_ from filesystem, and not
> accessing swap device.
> 
>    Should I fill in a bug report in kernel's bugzilla, or just upgrade
> the notebook? )
> 
If I remember correctly, there is a sysctl for configuring how
aggressively the system tries to retain the VFS cache, changing the
value there might improve things for you.