Re: KSM For All Via LD_PRELOAD?

[Jes Sorensen <Jes.Sorensen@redhat.com>]

On 06/08/10 20:43, Gordan Bobic wrote:
> Is this plausible?
> 
> I'm trying to work out if it's even worth considering this approach to
> enable all memory used by in a system to be open to KSM page merging,
> rather than only memory used by specific programs aware of it (e.g.
> kvm/qemu).
> 
> Something like this would address the fact that container based
> virtualization (OpenVZ, VServer, LXC) cannot benefit from KSM.
> 
> What I'm thinking about is somehow intercepting malloc() and wrapping it
> so that all malloc()-ed memory gets madvise()-d as well.

Not sure if it is worth it, but you might want to look at ElectricFence
which does malloc wrapping in a somewhat similar way. It might save you
some code :)

Whether or not you will run into problems if you run it system wise is
really hard to predict. Any other application that might be linked in a
special way or use preload itself might bark, but you can try it out and
see what explodes.

Cheers,
Jes