Virtual Memory Improvements For Linux 2.6.32 Kernel

Friday 4 December 2009

The Linux kernel with this week marking the debut of the kernel's fourth major updates.
The year's final update is the 2.6.32 kernel, which was released by Linux founder Linus Torvalds late Wednesday night.

The 2.6.32 is jam-packed full of driver and filesystem updates as well as several new features that are intended to improve both the physical and virtual performance of a Linux-based operating system.

BTRFS is a next-generation filesystem originally spearheaded by Oracle's Chris Mason. BTRFS holds the promise of providing improved error correction, "snapshotting" -- making a copy of file data at a particular point in time for improved data integrity and recovery
-- and other file-integrity enhancements.

BTRFS made its initial Linux kernel debut in the 2.6.29 kernel, the first update of 2009.

A new per-device writeback feature also originated with Oracle (NASDAQ: ORCL) by way of engineer Jens Axboe. The basic idea behind per-device writeback is to optimize the process by which so-called "dirty memory" -- memory that is not optimized and might need to be written to disk -- is flushed to a storage device.

The aim of per-device writeback is overall memory performance improvement, as the dirty memory can be optimized by use of its own dedicated kernel thread.

"As to the 'big feature' changes in 2.6.32 ... there's been a fair amount of changes to BTRFS, and the block-layer writeback itself has been through major updates, and the whole ... writeback thing is a pretty big change," Torvalds wrote in a mailing list post announcing the new kernel.