Re: [vserver] Unification and memory usage

From: Gordan Bobic <>
Date: Mon 02 May 2011 - 23:20:30 BST
Message-ID: <>

On 02/05/2011 23:14, Roderick A. Anderson wrote:
> I've got myself confused again. Could someone confirm or deny how
> unification affects memory usage.
> I was under the impression that if a unified (hard linked) "program" was
> started by one guest the code for it went into the text area of memory
> and any needed data area was allocated from the heap. Then when another
> guest started the same program kernel-magic happened and basically the
> same code was used but a new chunk of heap was allocated/used for its data.
> I'd like to make a simplified drawing of how the Linux-Vserver way with
> unification saves memory. Have I got it all wrong?

I believe the memory unification only applies to the shared memory
mmap-ed from hard-linked DLLs. If you have the same glibc unified across
all your guests, only one instance of it will be in memory. Unified
executables won't save you memory in this way.

What you will gain on all unified files, however, is caching efficiency,
as you won't end up with multiple copies of the same file being cached

Received on Mon May 2 23:20:47 2011

[Next/Previous Months] [Main vserver Project Homepage] [Howto Subscribe/Unsubscribe] [Paul Sladen's vserver stuff]
Generated on Mon 02 May 2011 - 23:20:47 BST by hypermail 2.1.8