Virtualization Technology News and Information
Linux kernel version 2.6.25 Released

Linux Kernel Newbies is reporting that Linux Kernel 2.6.25 is released and contains memory management enhancements needed for the virtualization environment.

The memory resource controller is a cgroups-based feature. Cgroups, aka "Control Groups", is a feature that was merged in 2.6.24, and its purpose is to be a generic framework where several "resource controllers" can plug in and manage different resources of the system such as process scheduling or memory allocation. It also offers a unified user interface, based on a virtual filesystem where administrators can assign arbitrary resource constraints to a group of chosen tasks. For example, in 2.6.24 they merged two resource controllers: Cpusets and Group Scheduling. The first allows to bind CPU and Memory nodes to the arbitrarily chosen group of tasks, aka cgroup, and the second allows to bind a CPU bandwidth policy to the cgroup.

The memory resource controller isolates the memory behavior of a group of tasks -cgroup- from the rest of the system. It can be used to:

  • Isolate an application or a group of applications. Memory hungry applications can be isolated and limited to a smaller amount of memory.
  • Create a cgroup with limited amount of memory, this can be used as a good alternative to booting with mem=XXXX.
  • Virtualization solutions can control the amount of memory they want to assign to a virtual machine instance.
  • A CD/DVD burner could control the amount of memory used by the rest of the system to ensure that burning does not fail due to lack of available memory.
Published Tuesday, April 22, 2008 7:03 PM by David Marshall
Filed under:
» Linux kernel version 2.6.25 Released - (Author's Link) - April 22, 2008 10:01 PM
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